diff --git a/file.c b/file.c
index 9b0e947..0333e9a 100644
--- a/file.c
+++ b/file.c
@@ -611,8 +611,10 @@ readHeader(URLFile *uf, Buffer *newBuf, int thru, ParsedURL *pu)
 	if(w3m_reqlog){
 	    FILE *ff;
 	    ff = fopen(w3m_reqlog, "a");
-	    Strfputs(tmp, ff);
-	    fclose(ff);
+            if(ff){
+	        Strfputs(tmp, ff);
+	        fclose(ff);
+            }
 	}
 	if (src)
 	    Strfputs(tmp, src);
@@ -7580,6 +7582,8 @@ loadImageBuffer(URLFile *uf, Buffer *newBuf)
     tmp = Sprintf("<img src=\"%s\"><br><br>", html_quote(image.url));
     tmpf = tmpfname(TMPF_SRC, ".html");
     src = fopen(tmpf->ptr, "w");
+    if (src == NULL)
+        return NULL;
     newBuf->mailcap_source = tmpf->ptr;
 
     init_stream(&f, SCM_LOCAL, newStrStream(tmp));
diff --git a/local.c b/local.c
index 46ac579..56d589d 100644
--- a/local.c
+++ b/local.c
@@ -426,7 +426,10 @@ localcgi_post(char *uri, char *qstr, FormList *request, char *referer)
     }
 
 #ifdef HAVE_CHDIR		/* ifndef __EMX__ ? */
-    chdir(cgi_dir);
+    if (chdir(cgi_dir) == -1) {
+        fprintf(stderr, "failed to chdir to %s: %s\n", cgi_dir, strerror(errno));
+        exit(1);
+    }
 #endif
     execl(file, cgi_basename, NULL);
     fprintf(stderr, "execl(\"%s\", \"%s\", NULL): %s\n",
diff --git a/url.c b/url.c
index d759383..348f501 100644
--- a/url.c
+++ b/url.c
@@ -1752,6 +1752,8 @@ openURL(char *url, ParsedURL *pu, ParsedURL *current,
 		write(sock, tmp->ptr, tmp->length);
 	    if(w3m_reqlog){
 		FILE *ff = fopen(w3m_reqlog, "a");
+		if (ff == NULL)
+		    return uf;
 		if (sslh)
 		    fputs("HTTPS: request via SSL\n", ff);
 		else
@@ -1774,6 +1776,8 @@ openURL(char *url, ParsedURL *pu, ParsedURL *current,
 	    write(sock, tmp->ptr, tmp->length);
 	    if(w3m_reqlog){
 		FILE *ff = fopen(w3m_reqlog, "a");
+		if (ff == NULL)
+		    return uf;
 		fwrite(tmp->ptr, sizeof(char), tmp->length, ff);
 		fclose(ff);
 	    }