diff --git a/releasenotes.md b/releasenotes.md
index ccd7c58c8..afead88ea 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -82,6 +82,7 @@
 - Bug when compile time subtracting a distinct type.
 - `insert_at` incorrectly prevented inserts at the end of a list.
 - Fix aligned alloc for Win32 targets.
+- Compiler didn't detect when a module name was used both as a generic and regular module.
 
 ### Stdlib changes
 
diff --git a/src/compiler/context.c b/src/compiler/context.c
index 4c5898b5b..2a740be7e 100644
--- a/src/compiler/context.c
+++ b/src/compiler/context.c
@@ -20,6 +20,13 @@ static inline bool create_module_or_check_name(CompilationUnit *unit, Path *modu
 	if (!module)
 	{
 		module = unit->module = compiler_find_or_create_module(module_name, parameters);
+		if ((parameters == NULL) == module->is_generic)
+		{
+			print_error_at(module_name->span, "'%s' is both used as regular and generic module, it can't be both.",
+						   module_name->module);
+			SEMA_NOTE(module->name, "The definition here is different.");
+			return false;
+		}
 	}
 	else
 	{
diff --git a/test/test_suite/module/module_generic_mixing.c3 b/test/test_suite/module/module_generic_mixing.c3
new file mode 100644
index 000000000..be62be825
--- /dev/null
+++ b/test/test_suite/module/module_generic_mixing.c3
@@ -0,0 +1,7 @@
+module test;
+fn void main() {}
+
+module test(<Type>); // #error: generic
+fn void test() {
+	Type a;
+}
\ No newline at end of file
diff --git a/test/test_suite/switch/switch_in_defer_macro.c3t b/test/test_suite/switch/switch_in_defer_macro.c3t
index f18dfe396..1f122f2f2 100644
--- a/test/test_suite/switch/switch_in_defer_macro.c3t
+++ b/test/test_suite/switch/switch_in_defer_macro.c3t
@@ -454,7 +454,7 @@ fn void! lex_uint()
         assert(kind == UINT, "got %s; want %s", kind, Kind.UINT);
     }
 }
-module lexer;
+module lexer2;
 import std::io;
 
 fn int main(String[] args)