diff --git a/lib/manager/terraform/providers.ts b/lib/manager/terraform/providers.ts
index a74b5ca53d6c53785511f8844ad1bc23ffee34a0..09e925df261d27b03f1bf8681c101a08666ab06d 100644
--- a/lib/manager/terraform/providers.ts
+++ b/lib/manager/terraform/providers.ts
@@ -36,7 +36,8 @@ export function extractTerraformProvider(
     }
 
     const line = lines[lineNumber];
-    if (line) {
+    // istanbul ignore next
+    if (is.string(line)) {
       // `{` will be counted wit +1 and `}` with -1. Therefore if we reach braceCounter == 0. We have found the end of the terraform block
       const openBrackets = (line.match(/\{/g) || []).length;
       const closedBrackets = (line.match(/\}/g) || []).length;
@@ -54,6 +55,9 @@ export function extractTerraformProvider(
           }
         }
       }
+    } else {
+      // stop - something went wrong
+      braceCounter = 0;
     }
     lineNumber += 1;
   } while (braceCounter !== 0);