diff --git a/src/mono/mono/metadata/class-init.c b/src/mono/mono/metadata/class-init.c
index 92ce8abddddbe9..2f834a8e78b84d 100644
--- a/src/mono/mono/metadata/class-init.c
+++ b/src/mono/mono/metadata/class-init.c
@@ -1805,7 +1805,7 @@ mono_compress_bitmap (uint8_t *dest, const uint8_t *bitmap, int size)
 	while (bitmap < end) {
 		if (*bitmap || numz == 255) {
 			if (dest) {
-				*dest++ = numz;
+				*dest++ = (uint8_t)numz;
 				*dest++ = *bitmap;
 			}
 			res += 2;
@@ -1819,7 +1819,7 @@ mono_compress_bitmap (uint8_t *dest, const uint8_t *bitmap, int size)
 	if (numz) {
 		res += 2;
 		if (dest) {
-			*dest++ = numz;
+			*dest++ = (uint8_t)numz;
 			*dest++ = 0;
 		}
 	}
diff --git a/src/mono/mono/metadata/class-internals.h b/src/mono/mono/metadata/class-internals.h
index bc8e9729702943..4f0b60c29d2f97 100644
--- a/src/mono/mono/metadata/class-internals.h
+++ b/src/mono/mono/metadata/class-internals.h
@@ -287,11 +287,7 @@ union _MonoClassSizes {
 		int generic_param_token; /* for generic param types, both var and mvar */
 };
 
-/* enabled only with small config for now: we might want to do it unconditionally */
-#ifdef MONO_SMALL_CONFIG
 #define COMPRESSED_INTERFACE_BITMAP 1
-#endif
-
 
 #ifdef ENABLE_CHECKED_BUILD_PRIVATE_TYPES
 #define MONO_CLASS_DEF_PRIVATE 1
diff --git a/src/mono/mono/metadata/class-setup-vtable.c b/src/mono/mono/metadata/class-setup-vtable.c
index 618e6b05019abe..2d0a245e033be0 100644
--- a/src/mono/mono/metadata/class-setup-vtable.c
+++ b/src/mono/mono/metadata/class-setup-vtable.c
@@ -346,10 +346,12 @@ mono_class_setup_interface_offsets_internal (MonoClass *klass, int cur_slot, int
 		}
 		if (!klass->interface_bitmap) {
 #ifdef COMPRESSED_INTERFACE_BITMAP
-			int i = mono_compress_bitmap (NULL, bitmap, bsize);
-			klass->interface_bitmap = mono_class_alloc0 (klass, i);
-			mono_compress_bitmap (klass->interface_bitmap, bitmap, bsize);
+			int len = mono_compress_bitmap (NULL, bitmap, bsize);
+			uint8_t *compressed_bitmap = mono_class_alloc0 (klass, len);
+			mono_compress_bitmap (compressed_bitmap, bitmap, bsize);
 			g_free (bitmap);
+
+			klass->interface_bitmap = compressed_bitmap;
 #else
 			klass->interface_bitmap = bitmap;
 #endif
diff --git a/src/mono/mono/mini/type-checking.c b/src/mono/mono/mini/type-checking.c
index 6f453f88610ff4..41b0f2c0054e5a 100644
--- a/src/mono/mono/mini/type-checking.c
+++ b/src/mono/mono/mini/type-checking.c
@@ -137,7 +137,7 @@ mini_emit_interface_bitmap_check (MonoCompile *cfg, int intf_bit_reg, int base_r
 #ifdef COMPRESSED_INTERFACE_BITMAP
 	MonoInst *args [2];
 	MonoInst *res, *ins;
-	NEW_LOAD_MEMBASE (cfg, ins, OP_LOAD_MEMBASE, ibitmap_reg, base_reg, offset);
+	NEW_LOAD_MEMBASE (cfg, ins, OP_LOAD_MEMBASE, ibitmap_reg, base_reg, (target_mgreg_t)offset);
 	MONO_ADD_INS (cfg->cbb, ins);
 	args [0] = ins;
 	args [1] = mini_emit_runtime_constant (cfg, MONO_PATCH_INFO_IID, klass);