diff --git a/test/023-many-interfaces/build b/test/023-many-interfaces/build
index 4ea52d9..ad42a2d 100644
--- a/test/023-many-interfaces/build
+++ b/test/023-many-interfaces/build
@@ -18,7 +18,7 @@
 set -e
 
 # Write out a bunch of interface source files.
-gcc -o iface-gen iface-gen.c
+gcc -Wall -Werror -o iface-gen iface-gen.c
 ./iface-gen
 
 mkdir classes
diff --git a/test/303-verification-stress/build b/test/303-verification-stress/build
index c1935d2..789d38e 100644
--- a/test/303-verification-stress/build
+++ b/test/303-verification-stress/build
@@ -18,7 +18,7 @@
 set -e
 
 # Write out a bunch of source files.
-gcc -o classes-gen classes-gen.c
+gcc -Wall -Werror -o classes-gen classes-gen.c
 ./classes-gen
 
 mkdir classes
diff --git a/test/303-verification-stress/classes-gen.c b/test/303-verification-stress/classes-gen.c
index be6cfa7..1f2fe3b 100644
--- a/test/303-verification-stress/classes-gen.c
+++ b/test/303-verification-stress/classes-gen.c
@@ -26,11 +26,11 @@
 
         fprintf(fp, "public class Test%03d {\n", i);
         fprintf(fp, "    static String[] array = new String[%d];\n", array_size);
-        fprintf(fp, "    static {\n", array_size);
+        fprintf(fp, "    static {\n");
         for (k = 0; k < array_size; k++) {
             fprintf(fp, "        array[%d] = \"string_%04d\";\n", k, k);
         }
-        fprintf(fp, "    }\n", array_size);
+        fprintf(fp, "    }\n");
         fprintf(fp, "}\n");
         fclose(fp);
     }