diff --git a/lib/openpam_load.c b/lib/openpam_load.c
index a1057f3..838f72e 100644
--- a/lib/openpam_load.c
+++ b/lib/openpam_load.c
@@ -31,7 +31,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $P4: //depot/projects/openpam/lib/openpam_load.c#19 $
+ * $P4: //depot/projects/openpam/lib/openpam_load.c#20 $
  */
 
 #include <dlfcn.h>
@@ -153,10 +153,13 @@ openpam_destroy_chain(pam_chain_t *chain)
 		return;
 	openpam_destroy_chain(chain->next);
 	chain->next = NULL;
-	while (chain->optc--)
+	while (chain->optc) {
+		--chain->optc;
 		FREE(chain->optv[chain->optc]);
+	}
 	FREE(chain->optv);
 	openpam_release_module(chain->module);
+	chain->module = NULL;
 	FREE(chain);
 }
 
diff --git a/lib/pam_end.c b/lib/pam_end.c
index e1762c6..0dd3ea7 100644
--- a/lib/pam_end.c
+++ b/lib/pam_end.c
@@ -31,7 +31,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $P4: //depot/projects/openpam/lib/pam_end.c#13 $
+ * $P4: //depot/projects/openpam/lib/pam_end.c#14 $
  */
 
 #include <stdlib.h>
@@ -68,8 +68,10 @@ pam_end(pam_handle_t *pamh,
 	}
 
 	/* clear environment */
-	while (pamh->env_count)
-		FREE(pamh->env[--pamh->env_count]);
+	while (pamh->env_count) {
+		--pamh->env_count;
+		FREE(pamh->env[pamh->env_count]);
+	}
 	FREE(pamh->env);
 
 	/* clear chains */
diff --git a/lib/pam_getenvlist.c b/lib/pam_getenvlist.c
index 2ba1bdf..82f2320 100644
--- a/lib/pam_getenvlist.c
+++ b/lib/pam_getenvlist.c
@@ -31,7 +31,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $P4: //depot/projects/openpam/lib/pam_getenvlist.c#12 $
+ * $P4: //depot/projects/openpam/lib/pam_getenvlist.c#13 $
  */
 
 #include <stdlib.h>
@@ -65,8 +65,10 @@ pam_getenvlist(pam_handle_t *pamh)
 	}
 	for (i = 0; i < pamh->env_count; ++i) {
 		if ((envlist[i] = strdup(pamh->env[i])) == NULL) {
-			while (i)
-				FREE(envlist[--i]);
+			while (i) {
+				--i;
+				FREE(envlist[i]);
+			}
 			FREE(envlist);
 			openpam_log(PAM_LOG_ERROR, "%s",
 				pam_strerror(pamh, PAM_BUF_ERR));