diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 663ad7bcea6e..29ab2f6946c7 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -16,12 +16,6 @@ jobs:
     strategy:
       matrix:
         crystal_bootstrap_version: [1.2.2, 1.3.2, 1.4.1, 1.5.1, 1.6.2, 1.7.0]
-        include:
-          # libffi is only available starting from the 1.2.2 build images
-          - crystal_bootstrap_version: 1.0.0
-            flags: -Dwithout_ffi
-          - crystal_bootstrap_version: 1.1.1
-            flags: -Dwithout_ffi
     steps:
       - name: Download Crystal source
         uses: actions/checkout@v3
diff --git a/spec/std/float_spec.cr b/spec/std/float_spec.cr
index b93597c389c6..a9316e888b4a 100644
--- a/spec/std/float_spec.cr
+++ b/spec/std/float_spec.cr
@@ -327,25 +327,21 @@ describe "Float" do
     (-0.0/0.0).finite?.should be_false
   end
 
-  {% if compare_versions(Crystal::VERSION, "0.36.1") > 0 %}
-    it "converts infinity" do
-      Float32::INFINITY.to_f64.infinite?.should eq 1
-      Float32::INFINITY.to_f32.infinite?.should eq 1
-      expect_raises(OverflowError) { Float32::INFINITY.to_i }
-      (-Float32::INFINITY).to_f64.infinite?.should eq -1
-      (-Float32::INFINITY).to_f32.infinite?.should eq -1
-      expect_raises(OverflowError) { (-Float32::INFINITY).to_i }
-
-      Float64::INFINITY.to_f64.infinite?.should eq 1
-      Float64::INFINITY.to_f32.infinite?.should eq 1
-      expect_raises(OverflowError) { Float64::INFINITY.to_i }
-      (-Float64::INFINITY).to_f64.infinite?.should eq -1
-      (-Float64::INFINITY).to_f32.infinite?.should eq -1
-      expect_raises(OverflowError) { (-Float64::INFINITY).to_i }
-    end
-  {% else %}
-    pending "converts infinity"
-  {% end %}
+  it "converts infinity" do
+    Float32::INFINITY.to_f64.infinite?.should eq 1
+    Float32::INFINITY.to_f32.infinite?.should eq 1
+    expect_raises(OverflowError) { Float32::INFINITY.to_i }
+    (-Float32::INFINITY).to_f64.infinite?.should eq -1
+    (-Float32::INFINITY).to_f32.infinite?.should eq -1
+    expect_raises(OverflowError) { (-Float32::INFINITY).to_i }
+
+    Float64::INFINITY.to_f64.infinite?.should eq 1
+    Float64::INFINITY.to_f32.infinite?.should eq 1
+    expect_raises(OverflowError) { Float64::INFINITY.to_i }
+    (-Float64::INFINITY).to_f64.infinite?.should eq -1
+    (-Float64::INFINITY).to_f32.infinite?.should eq -1
+    expect_raises(OverflowError) { (-Float64::INFINITY).to_i }
+  end
 
   it "does unary -" do
     f = -(1.5)
diff --git a/spec/std/number_spec.cr b/spec/std/number_spec.cr
index 0b703d7199d0..b517c3cc7cb8 100644
--- a/spec/std/number_spec.cr
+++ b/spec/std/number_spec.cr
@@ -69,20 +69,16 @@ describe "Number" do
       (-Float64::INFINITY).round(digits: -3).should eq -Float64::INFINITY
     end
 
-    {% if compare_versions(Crystal::VERSION, "0.36.1") > 0 %}
-      it "infinity Float32" do
-        Float32::INFINITY.round.should eq Float32::INFINITY
-        Float32::INFINITY.round(digits: 0).should eq Float32::INFINITY
-        Float32::INFINITY.round(digits: 3).should eq Float32::INFINITY
-        Float32::INFINITY.round(digits: -3).should eq Float32::INFINITY
-        (-Float32::INFINITY).round.should eq -Float32::INFINITY
-        (-Float32::INFINITY).round(digits: 0).should eq -Float32::INFINITY
-        (-Float32::INFINITY).round(digits: 3).should eq -Float32::INFINITY
-        (-Float32::INFINITY).round(digits: -3).should eq -Float32::INFINITY
-      end
-    {% else %}
-      pending "infinity Float32"
-    {% end %}
+    it "infinity Float32" do
+      Float32::INFINITY.round.should eq Float32::INFINITY
+      Float32::INFINITY.round(digits: 0).should eq Float32::INFINITY
+      Float32::INFINITY.round(digits: 3).should eq Float32::INFINITY
+      Float32::INFINITY.round(digits: -3).should eq Float32::INFINITY
+      (-Float32::INFINITY).round.should eq -Float32::INFINITY
+      (-Float32::INFINITY).round(digits: 0).should eq -Float32::INFINITY
+      (-Float32::INFINITY).round(digits: 3).should eq -Float32::INFINITY
+      (-Float32::INFINITY).round(digits: -3).should eq -Float32::INFINITY
+    end
 
     it "nan" do
       Float64::NAN.round.nan?.should be_true
diff --git a/src/compiler/crystal.cr b/src/compiler/crystal.cr
index e6924d4d5248..884c0eed50bc 100644
--- a/src/compiler/crystal.cr
+++ b/src/compiler/crystal.cr
@@ -3,6 +3,11 @@
 
 {% raise("Please use `make crystal` to build the compiler, or set the i_know_what_im_doing flag if you know what you're doing") unless env("CRYSTAL_HAS_WRAPPER") || flag?("i_know_what_im_doing") %}
 
+{%
+  version = "1.2.0"
+  raise("Compiling Crystal requires at least version #{version.id} of Crystal. Current version is #{Crystal::VERSION}") if compare_versions(Crystal::VERSION, version.id) < 0
+%}
+
 require "log"
 require "./requires"
 
diff --git a/src/indexable/mutable.cr b/src/indexable/mutable.cr
index 86331554f924..3d2fef37b192 100644
--- a/src/indexable/mutable.cr
+++ b/src/indexable/mutable.cr
@@ -213,7 +213,6 @@ module Indexable::Mutable(T)
     end
   end
 
-  {% begin %}
   # Invokes the given block for each element of `self`, replacing the element
   # with the value returned by the block. Returns `self`.
   #
@@ -222,17 +221,12 @@ module Indexable::Mutable(T)
   # a.map! { |x| x * x }
   # a # => [1, 4, 9]
   # ```
-  {% if compare_versions(Crystal::VERSION, "1.1.1") >= 0 %}
   def map!(& : T -> _) : self # TODO: add as constant
-  {% else %}
-  def map!(&) # it doesn't compile with the type annotation in the 1.0.0 compiler
-  {% end %}
     each_index do |i|
       unsafe_put(i, yield unsafe_fetch(i))
     end
     self
   end
-  {% end %}
 
   # Like `#map!`, but the block gets passed both the element and its index.
   #
diff --git a/src/unicode/unicode.cr b/src/unicode/unicode.cr
index 6a9a7698c3d4..5f630445ea83 100644
--- a/src/unicode/unicode.cr
+++ b/src/unicode/unicode.cr
@@ -132,21 +132,12 @@ module Unicode
     array << value
   end
 
-  # TODO: remove the workaround for 1.0.0 eventually (needed until #10713)
   private macro dfa_state(*transitions)
-    {% if compare_versions(Crystal::VERSION, "1.1.0") >= 0 %}
-      {% x = 0_u64 %}
-      {% for tr, i in transitions %}
-        {% x |= (1_u64 << (i * 6)) * tr * 6 %}
-      {% end %}
-      {{ x }}
-    {% else %}
-      {% x = [] of Nil %}
-      {% for tr, i in transitions %}
-        {% x << "(#{tr * 6}_u64 << #{i * 6})" %}
-      {% end %}
-      {{ x.join(" | ").id }}
+    {% x = 0_u64 %}
+    {% for tr, i in transitions %}
+      {% x |= (1_u64 << (i * 6)) * tr * 6 %}
     {% end %}
+    {{ x }}
   end
 
   # :nodoc: