diff --git a/.appveyor.yml b/.appveyor.yml
index 5c138b94..2bf46ade 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -19,8 +19,8 @@ build_script:
       copy "build\release\bin\*" "${dir}\build\release\bin"
       copy -recurse "build\LLVM-5.0.1-win64\lib\clang\5.0.1\include" "${dir}\build\release\lib\LLVM-5.0.1-win64\lib\clang\5.0.1\"
       7z a -tzip "C:\projects\cquery\${dir}.zip" "${dir}"
-  - build\release\bin\cquery --log-all-to-stderr --test-unit
-  - build\release\bin\cquery --log-all-to-stderr --test-index
+  - build\release\bin\cquery --ci --log-all-to-stderr --test-unit
+  - build\release\bin\cquery --ci --log-all-to-stderr --test-index
 
 artifacts:
   - path: 'cquery-*.zip'
diff --git a/.travis.yml b/.travis.yml
index 246ef67d..a0940b4f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -195,8 +195,8 @@ before_script:
 script:
   - travis_retry ./waf configure
   - ./waf build
-  - ./build/release/bin/cquery --log-all-to-stderr --test-unit
-  - ./build/release/bin/cquery --log-all-to-stderr --test-index
+  - ./build/release/bin/cquery --ci --log-all-to-stderr --test-unit
+  - ./build/release/bin/cquery --ci --log-all-to-stderr --test-index
 
 notifications:
   email: false
diff --git a/src/command_line.cc b/src/command_line.cc
index 10be4cd2..5178a6dc 100644
--- a/src/command_line.cc
+++ b/src/command_line.cc
@@ -430,7 +430,8 @@ int main(int argc, char** argv) {
 
   if (HasOption(options, "--test-index")) {
     print_help = false;
-    RunIndexTests(options["--test-index"]);
+    if (!RunIndexTests(options["--test-index"], !HasOption(options, "--ci")))
+      return -1;
   }
 
   if (HasOption(options, "--enable-comments")) {
@@ -483,6 +484,9 @@ Command line options:
                 If true, cquery will wait for an '[Enter]' before exiting.
                 Useful on windows.
   --help        Print this help information.
+  --ci          Prevents tests from prompting the user for input. Used for
+                continuous integration so it can fail faster instead of timing
+                out.
 
 Configuration:
   When opening up a directory, cquery will look for a compile_commands.json file
diff --git a/src/test.cc b/src/test.cc
index cb6d7ba5..4a5f4802 100644
--- a/src/test.cc
+++ b/src/test.cc
@@ -108,7 +108,7 @@ IndexFile* FindDbForPathEnding(
   return nullptr;
 }
 
-void RunIndexTests(const std::string& filter_path) {
+bool RunIndexTests(const std::string& filter_path, bool enable_update) {
   SetTestOutputMode();
 
   // Index tests change based on the version of clang used.
@@ -121,6 +121,7 @@ void RunIndexTests(const std::string& filter_path) {
     exit(1);
   }
 
+  bool success = true;
   bool update_all = false;
   ClangIndex index;
 
@@ -226,28 +227,33 @@ void RunIndexTests(const std::string& filter_path) {
       if (actual == expected) {
         // std::cout << "[PASSED] " << path << std::endl;
       } else {
+        success = false;
         DiffDocuments(path, expected_path, expected, actual);
         std::cout << std::endl;
         std::cout << std::endl;
-        std::cout
+        if (enable_update) {
+          std::cout
             << "[Enter to continue - type u to update test, a to update all]";
-        char c = 'u';
-        if (!update_all) {
-          c = (char)std::cin.get();
-          std::cin.get();
-        }
+          char c = 'u';
+          if (!update_all) {
+            c = (char)std::cin.get();
+            std::cin.get();
+          }
 
-        if (c == 'a')
-          update_all = true;
+          if (c == 'a')
+            update_all = true;
 
-        if (update_all || c == 'u') {
-          // Note: we use |entry.second| instead of |expected_output| because
-          // |expected_output| has had text replacements applied.
-          UpdateTestExpectation(path, entry.second, ToString(actual) + "\n");
+          if (update_all || c == 'u') {
+            // Note: we use |entry.second| instead of |expected_output| because
+            // |expected_output| has had text replacements applied.
+            UpdateTestExpectation(path, entry.second, ToString(actual) + "\n");
+          }
         }
       }
     }
   }
+
+  return success;
 }
 
 // TODO: ctor/dtor, copy ctor
diff --git a/src/test.h b/src/test.h
index 3e88f02c..294d1ff9 100644
--- a/src/test.h
+++ b/src/test.h
@@ -2,4 +2,4 @@
 
 #include <string>
 
-void RunIndexTests(const std::string& filter_path);
+bool RunIndexTests(const std::string& filter_path, bool enable_update);