diff --git a/tests/checkasm/lpc.c b/tests/checkasm/lpc.c
index 49e608f8c1..2823953878 100644
--- a/tests/checkasm/lpc.c
+++ b/tests/checkasm/lpc.c
@@ -22,12 +22,12 @@
 
 #include "checkasm.h"
 
-#define randomize_int32(buf, len)       \
-    do {                                \
-        for (int i = 0; i < len; i++) { \
-            int32_t f = rnd() >> 8;     \
-            buf[i] = f;                 \
-        }                               \
+#define randomize_int32(buf, len)                          \
+    do {                                                   \
+        for (int i = 0; i < len; i++) {                    \
+            int32_t f = (UINT32_MAX >> 8) - (rnd() >> 16); \
+            buf[i] = f;                                    \
+        }                                                  \
     } while (0)
 
 #define EPS 0.005