diff --git a/gsk/gskslpreprocessor.c b/gsk/gskslpreprocessor.c
index 6f748ffdfc..6a1c6fe321 100644
--- a/gsk/gskslpreprocessor.c
+++ b/gsk/gskslpreprocessor.c
@@ -295,6 +295,15 @@ gsk_sl_preprocessor_append_token (GskSlPreprocessor *preproc,
       return;
     }
 
+  if (gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_EOF))
+    {
+      while (gsk_sl_preprocessor_has_conditional (preproc))
+        {
+          gsk_sl_preprocessor_pop_conditional (preproc);
+          gsk_sl_preprocessor_error_full (preproc, PREPROCESSOR, &pp->location, "Missing #endif.");
+        }
+    }
+
   if (gsk_sl_preprocessor_in_ignored_conditional (preproc))
     {
       gsk_sl_preprocessor_clear_token (pp);
diff --git a/testsuite/gsksl/errors/missing-endif-after-if-0.glsl b/testsuite/gsksl/errors/missing-endif-after-if-0.glsl
new file mode 100644
index 0000000000..91f3636006
--- /dev/null
+++ b/testsuite/gsksl/errors/missing-endif-after-if-0.glsl
@@ -0,0 +1,6 @@
+#if 0
+
+void
+main ()
+{
+}
diff --git a/testsuite/gsksl/errors/missing-endif-after-if-1.glsl b/testsuite/gsksl/errors/missing-endif-after-if-1.glsl
new file mode 100644
index 0000000000..d44b83052a
--- /dev/null
+++ b/testsuite/gsksl/errors/missing-endif-after-if-1.glsl
@@ -0,0 +1,6 @@
+#if 1
+
+void
+main ()
+{
+}