diff --git a/packages/angular_devkit/build_angular/src/app-shell/schema.json b/packages/angular_devkit/build_angular/src/app-shell/schema.json
index e7fb6156d47f..b89b795265ab 100644
--- a/packages/angular_devkit/build_angular/src/app-shell/schema.json
+++ b/packages/angular_devkit/build_angular/src/app-shell/schema.json
@@ -6,11 +6,13 @@
   "properties": {
     "browserTarget": {
       "type": "string",
-      "description": "Target to build."
+      "description": "Target to build.",
+      "pattern": "^[^:\\s]+:[^:\\s]+(:[^\\s]+)?$"
     },
     "serverTarget": {
       "type": "string",
-      "description": "Server target to use for rendering the app shell."
+      "description": "Server target to use for rendering the app shell.",
+      "pattern": "^[^:\\s]+:[^:\\s]+(:[^\\s]+)?$"
     },
     "appModuleBundle": {
       "type": "string",
diff --git a/packages/angular_devkit/build_angular/src/dev-server/schema.json b/packages/angular_devkit/build_angular/src/dev-server/schema.json
index ff1623b9d55b..8901b27cc9b8 100644
--- a/packages/angular_devkit/build_angular/src/dev-server/schema.json
+++ b/packages/angular_devkit/build_angular/src/dev-server/schema.json
@@ -7,7 +7,7 @@
     "browserTarget": {
       "type": "string",
       "description": "Target to serve.",
-      "pattern": ".+:.+(:.+)?"
+      "pattern": "^[^:\\s]+:[^:\\s]+(:[^\\s]+)?$"
     },
     "port": {
       "type": "number",
diff --git a/packages/angular_devkit/build_angular/src/extract-i18n/schema.json b/packages/angular_devkit/build_angular/src/extract-i18n/schema.json
index 3212818ff580..2d9d89c170be 100644
--- a/packages/angular_devkit/build_angular/src/extract-i18n/schema.json
+++ b/packages/angular_devkit/build_angular/src/extract-i18n/schema.json
@@ -6,7 +6,8 @@
   "properties": {
     "browserTarget": {
       "type": "string",
-      "description": "Target to extract from."
+      "description": "Target to extract from.",
+      "pattern": "^[^:\\s]+:[^:\\s]+(:[^\\s]+)?$"
     },
     "format": {
       "type": "string",
diff --git a/packages/angular_devkit/build_angular/src/protractor/schema.json b/packages/angular_devkit/build_angular/src/protractor/schema.json
index 0da1ccc1dff8..9eeb1c22a557 100644
--- a/packages/angular_devkit/build_angular/src/protractor/schema.json
+++ b/packages/angular_devkit/build_angular/src/protractor/schema.json
@@ -10,7 +10,8 @@
     },
     "devServerTarget": {
       "type": "string",
-      "description": "Dev server target to run tests against."
+      "description": "Dev server target to run tests against.",
+      "pattern": "^([^:\\s]+:[^:\\s]+(:[^\\s]+)?)?$"
     },
     "specs": {
       "type": "array",