diff --git a/cmd/selfserv/selfserv.c b/cmd/selfserv/selfserv.c
--- a/cmd/selfserv/selfserv.c
+++ b/cmd/selfserv/selfserv.c
@@ -2078,13 +2078,13 @@
     if (!input || !input->data || input->len == 0 || !output || outputLen == 0) {
         PR_SetError(SEC_ERROR_INVALID_ARGS, 0);
         return SECFailure;
     }
 
-    *usedLen = outputLen;
-
-    int ret = uncompress(output, (unsigned long *)usedLen, input->data, input->len);
+    unsigned long outputLenUL = outputLen;
+    int ret = uncompress(output, &outputLenUL, input->data, input->len);
+    *usedLen = outputLenUL;
     if (ret != Z_OK) {
         PR_SetError(SEC_ERROR_BAD_DATA, 0);
         return SECFailure;
     }
 
@@ -2100,11 +2100,13 @@
     }
 
     unsigned long maxCompressedLen = compressBound(input->len);
     SECITEM_AllocItem(NULL, output, maxCompressedLen);
 
-    int ret = compress(output->data, (unsigned long *)&output->len, input->data, input->len);
+    unsigned long outputLenUL = output->len;
+    int ret = compress(output->data, &outputLenUL, input->data, input->len);
+    output->len = outputLenUL;
     if (ret != Z_OK) {
         PR_SetError(SEC_ERROR_LIBRARY_FAILURE, 0);
         return SECFailure;
     }
 
diff --git a/cmd/tstclnt/tstclnt.c b/cmd/tstclnt/tstclnt.c
--- a/cmd/tstclnt/tstclnt.c
+++ b/cmd/tstclnt/tstclnt.c
@@ -1375,11 +1375,13 @@
     }
 
     unsigned long maxCompressedLen = compressBound(input->len);
     SECITEM_AllocItem(NULL, output, maxCompressedLen);
 
-    int ret = compress(output->data, (unsigned long *)&output->len, input->data, input->len);
+    unsigned long outputLenUL = output->len;
+    int ret = compress(output->data, &outputLenUL, input->data, input->len);
+    output->len = outputLenUL;
     if (ret != Z_OK) {
         PR_SetError(SEC_ERROR_LIBRARY_FAILURE, 0);
         return SECFailure;
     }
 
@@ -1394,13 +1396,13 @@
     if (!input || !input->data || input->len == 0 || !output || outputLen == 0) {
         PR_SetError(SEC_ERROR_INVALID_ARGS, 0);
         return SECFailure;
     }
 
-    *usedLen = outputLen;
-
-    int ret = uncompress(output, (unsigned long *)usedLen, input->data, input->len);
+    unsigned long outputLenUL = outputLen;
+    int ret = uncompress(output, &outputLenUL, input->data, input->len);
+    *usedLen = outputLenUL;
     if (ret != Z_OK) {
         PR_SetError(SEC_ERROR_BAD_DATA, 0);
         return SECFailure;
     }