diff --git a/base64_from.c b/base64_from.c
index aabd84f..808bf1d 100644
--- a/base64_from.c
+++ b/base64_from.c
@@ -84,6 +84,9 @@ int base64_valid(const char *src,size_t *count)
 	for (p = src;base64f[(u8)*p] != 0xFF;++p)
 		;
 
+	for (;*p == '=';++p)
+		;
+
 	if (count)
 		*count = (size_t) (p - src);
 	return !*p;
diff --git a/main.c b/main.c
index 80e3df3..79552a3 100644
--- a/main.c
+++ b/main.c
@@ -667,22 +667,6 @@ int main(int argc,char **argv)
 		exit(Q_FAILOPENOUTPUT); // define new err code?
 	}
 
-	filters_prepare();
-
-	filters_print();
-
-#ifdef STATISTICS
-	if (!filters_count() && !reportdelay)
-#else
-	if (!filters_count())
-#endif
-		return 0;
-
-#ifdef EXPANDMASK
-	if (numwords > 1 && flattened)
-		fprintf(stderr,"WARNING: -N switch will produce bogus results because we can't know filter width. reconfigure with --enable-besort and recompile.\n");
-#endif
-
 	if (workdir)
 		createdir(workdir,1);
 
@@ -720,6 +704,22 @@ int main(int argc,char **argv)
 		goto done;
 	}
 
+	filters_prepare();
+
+	filters_print();
+
+#ifdef STATISTICS
+	if (!filters_count() && !reportdelay)
+#else
+	if (!filters_count())
+#endif
+		return 0;
+
+#ifdef EXPANDMASK
+	if (numwords > 1 && flattened)
+		fprintf(stderr,"WARNING: -N switch will produce bogus results because we can't know filter width. reconfigure with --enable-besort and recompile.\n");
+#endif
+
 	if (yamloutput)
 		yamlout_init();
 
diff --git a/test_base64.c b/test_base64.c
index cebb030..bd7fbf6 100644
--- a/test_base64.c
+++ b/test_base64.c
@@ -32,6 +32,10 @@ int main(void)
 						 tests0[i].in, buf, tests0[i].out);
 			return 1;
 		}
+		if (!base64_valid(buf,0)) {
+			printf("encoded data is considered invalid\n");
+			return 3;
+		}
 		r = base64_from((u8 *)buf2, buf, strlen(buf));
 		buf2[r] = '\0';
 		if (strcmp(buf2, tests0[i].rev) != 0) {