diff --git a/compiler/noirc_frontend/proptest-regressions/parser/parser/types.txt b/compiler/noirc_frontend/proptest-regressions/parser/parser/types.txt
new file mode 100644
index 00000000000..1fe60c7bd7c
--- /dev/null
+++ b/compiler/noirc_frontend/proptest-regressions/parser/parser/types.txt
@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc 658af2bccf8d12d4c30396c9efbe63f8cb0992355943516aacdcd41221a399ed # shrinks to sign = 'i', width = 1
diff --git a/compiler/noirc_frontend/src/ast/mod.rs b/compiler/noirc_frontend/src/ast/mod.rs
index 47b70ed654e..dd3a1e1464b 100644
--- a/compiler/noirc_frontend/src/ast/mod.rs
+++ b/compiler/noirc_frontend/src/ast/mod.rs
@@ -393,6 +393,8 @@ impl UnresolvedTypeData {
             Signed(num_bits) => {
                 if num_bits == 128 {
                     Err(InvalidIntegerBitSizeError(128))
+                } else if num_bits == 1 {
+                    Err(InvalidIntegerBitSizeError(1))
                 } else {
                     Ok(Integer(Signedness::Signed, IntegerBitSize::try_from(num_bits)?))
                 }
diff --git a/compiler/noirc_frontend/src/parser/parser/types.rs b/compiler/noirc_frontend/src/parser/parser/types.rs
index d07294e2c9d..b399441ad03 100644
--- a/compiler/noirc_frontend/src/parser/parser/types.rs
+++ b/compiler/noirc_frontend/src/parser/parser/types.rs
@@ -470,6 +470,9 @@ impl Parser<'_> {
 
 #[cfg(test)]
 mod tests {
+    use std::collections::BTreeMap;
+
+    use proptest::prelude::*;
     use strum::IntoEnumIterator;
 
     use crate::{
@@ -513,26 +516,41 @@ mod tests {
         ));
     }
 
-    #[test]
-    fn errors_on_invalid_bit_size() {
-        let src = "u31";
-        let mut parser = Parser::for_str_with_dummy_file(src);
-        let typ = parser.parse_type_or_error();
-        assert_eq!(typ.typ, UnresolvedTypeData::Error);
-        assert_eq!(parser.errors.len(), 1);
-        let error = &parser.errors[0];
-        assert!(matches!(error.reason(), Some(ParserErrorReason::InvalidBitSize(..))));
-    }
-
-    #[test]
-    fn errors_on_i128() {
-        let src = "i128";
-        let mut parser = Parser::for_str_with_dummy_file(src);
-        let typ = parser.parse_type_or_error();
-        assert_eq!(typ.typ, UnresolvedTypeData::Error);
-        assert_eq!(parser.errors.len(), 1);
-        let error = &parser.errors[0];
-        assert!(matches!(error.reason(), Some(ParserErrorReason::InvalidBitSize(..))));
+    proptest! {
+        #[test]
+        fn parses_only_expected_types(sign in proptest::prop_oneof![Just('u'), Just('i')], width: u8) {
+            let accepted_types = BTreeMap::from([
+                ("u1", UnresolvedTypeData::Integer(Signedness::Unsigned, IntegerBitSize::One)),
+                ("u8", UnresolvedTypeData::Integer(Signedness::Unsigned, IntegerBitSize::Eight)),
+                ("u16", UnresolvedTypeData::Integer(Signedness::Unsigned, IntegerBitSize::Sixteen)),
+                ("u32", UnresolvedTypeData::Integer(Signedness::Unsigned, IntegerBitSize::ThirtyTwo)),
+                ("u64", UnresolvedTypeData::Integer(Signedness::Unsigned, IntegerBitSize::SixtyFour)),
+                (
+                    "u128",
+                    UnresolvedTypeData::Integer(
+                        Signedness::Unsigned,
+                        IntegerBitSize::HundredTwentyEight,
+                    ),
+                ),
+                ("i8", UnresolvedTypeData::Integer(Signedness::Signed, IntegerBitSize::Eight)),
+                ("i16", UnresolvedTypeData::Integer(Signedness::Signed, IntegerBitSize::Sixteen)),
+                ("i32", UnresolvedTypeData::Integer(Signedness::Signed, IntegerBitSize::ThirtyTwo)),
+                ("i64", UnresolvedTypeData::Integer(Signedness::Signed, IntegerBitSize::SixtyFour)),
+            ]);
+
+            let src = format!("{sign}{width}");
+            let mut parser = Parser::for_str_with_dummy_file(&src);
+            let typ = parser.parse_type_or_error();
+
+            if let Some(expected_typ) = accepted_types.get(&src.as_str()) {
+                assert_eq!(&typ.typ, expected_typ);
+            } else {
+                assert_eq!(typ.typ, UnresolvedTypeData::Error);
+                assert_eq!(parser.errors.len(), 1);
+                let error = &parser.errors[0];
+                assert!(matches!(error.reason(), Some(ParserErrorReason::InvalidBitSize(..))));
+            }
+        }
     }
 
     #[test]
diff --git a/test_programs/execution_success/array_oob_regression_7975/src/main.nr b/test_programs/execution_success/array_oob_regression_7975/src/main.nr
index 81ef03579ee..49cdc5373c5 100644
--- a/test_programs/execution_success/array_oob_regression_7975/src/main.nr
+++ b/test_programs/execution_success/array_oob_regression_7975/src/main.nr
@@ -1,4 +1,4 @@
-fn main(b: [[i1; 1]; 1]) -> pub [[i1; 1]; 1] {
+fn main(b: [[u1; 1]; 1]) -> pub [[u1; 1]; 1] {
     if (b[0][0] == b[0][0]) {
         b
     } else {
diff --git a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_-9223372036854775808.snap b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_-9223372036854775808.snap
index f0ae33c4946..99ebbcdb1c6 100644
--- a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_-9223372036854775808.snap
+++ b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_-9223372036854775808.snap
@@ -17,7 +17,7 @@ expression: artifact
             "length": 1,
             "type": {
               "kind": "integer",
-              "sign": "signed",
+              "sign": "unsigned",
               "width": 1
             }
           }
@@ -34,7 +34,7 @@ expression: artifact
           "length": 1,
           "type": {
             "kind": "integer",
-            "sign": "signed",
+            "sign": "unsigned",
             "width": 1
           }
         }
diff --git a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_0.snap b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_0.snap
index f0ae33c4946..99ebbcdb1c6 100644
--- a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_0.snap
+++ b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_0.snap
@@ -17,7 +17,7 @@ expression: artifact
             "length": 1,
             "type": {
               "kind": "integer",
-              "sign": "signed",
+              "sign": "unsigned",
               "width": 1
             }
           }
@@ -34,7 +34,7 @@ expression: artifact
           "length": 1,
           "type": {
             "kind": "integer",
-            "sign": "signed",
+            "sign": "unsigned",
             "width": 1
           }
         }
diff --git a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_9223372036854775807.snap b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_9223372036854775807.snap
index f0ae33c4946..99ebbcdb1c6 100644
--- a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_9223372036854775807.snap
+++ b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_false_inliner_9223372036854775807.snap
@@ -17,7 +17,7 @@ expression: artifact
             "length": 1,
             "type": {
               "kind": "integer",
-              "sign": "signed",
+              "sign": "unsigned",
               "width": 1
             }
           }
@@ -34,7 +34,7 @@ expression: artifact
           "length": 1,
           "type": {
             "kind": "integer",
-            "sign": "signed",
+            "sign": "unsigned",
             "width": 1
           }
         }
diff --git a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_-9223372036854775808.snap b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_-9223372036854775808.snap
index 5f23465c8fa..fb92bca973b 100644
--- a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_-9223372036854775808.snap
+++ b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_-9223372036854775808.snap
@@ -17,7 +17,7 @@ expression: artifact
             "length": 1,
             "type": {
               "kind": "integer",
-              "sign": "signed",
+              "sign": "unsigned",
               "width": 1
             }
           }
@@ -34,7 +34,7 @@ expression: artifact
           "length": 1,
           "type": {
             "kind": "integer",
-            "sign": "signed",
+            "sign": "unsigned",
             "width": 1
           }
         }
diff --git a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_0.snap b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_0.snap
index 5f23465c8fa..fb92bca973b 100644
--- a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_0.snap
+++ b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_0.snap
@@ -17,7 +17,7 @@ expression: artifact
             "length": 1,
             "type": {
               "kind": "integer",
-              "sign": "signed",
+              "sign": "unsigned",
               "width": 1
             }
           }
@@ -34,7 +34,7 @@ expression: artifact
           "length": 1,
           "type": {
             "kind": "integer",
-            "sign": "signed",
+            "sign": "unsigned",
             "width": 1
           }
         }
diff --git a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_9223372036854775807.snap b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_9223372036854775807.snap
index 5f23465c8fa..fb92bca973b 100644
--- a/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_9223372036854775807.snap
+++ b/tooling/nargo_cli/tests/snapshots/execution_success/array_oob_regression_7975/execute__tests__force_brillig_true_inliner_9223372036854775807.snap
@@ -17,7 +17,7 @@ expression: artifact
             "length": 1,
             "type": {
               "kind": "integer",
-              "sign": "signed",
+              "sign": "unsigned",
               "width": 1
             }
           }
@@ -34,7 +34,7 @@ expression: artifact
           "length": 1,
           "type": {
             "kind": "integer",
-            "sign": "signed",
+            "sign": "unsigned",
             "width": 1
           }
         }