diff --git a/evaluator/flags/testkit-flags.json b/evaluator/flags/testkit-flags.json
index ce24194..fc696d4 100644
--- a/evaluator/flags/testkit-flags.json
+++ b/evaluator/flags/testkit-flags.json
@@ -511,6 +511,78 @@
       "targeting": {
         "if": [{"sem_ver": [{"var": "version"}, "=", "1.0.0+build"]}, "match", "no-match"]
       }
+    },
+    "ref-whitespace-compact-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hi": "hi",
+        "bye": "bye",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref":"is_ballmer"
+          },
+          "hi",
+          "bye"
+        ]
+      }
+    },
+    "ref-whitespace-space-after-colon-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hi": "hi",
+        "bye": "bye",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref": "is_ballmer"
+          },
+          "hi",
+          "bye"
+        ]
+      }
+    },
+    "ref-whitespace-space-around-colon-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hi": "hi",
+        "bye": "bye",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref" : "is_ballmer"
+          },
+          "hi",
+          "bye"
+        ]
+      }
+    },
+    "ref-to-nonexistent-evaluator-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hit": "hit",
+        "miss": "miss",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref": "nonexistent_evaluator"
+          },
+          "hit",
+          "miss"
+        ]
+      }
     }
   },
   "$evaluators": {
diff --git a/evaluator/gherkin/evaluator-refs.feature b/evaluator/gherkin/evaluator-refs.feature
index 0d8467d..1e2ffd4 100644
--- a/evaluator/gherkin/evaluator-refs.feature
+++ b/evaluator/gherkin/evaluator-refs.feature
@@ -13,3 +13,28 @@ Feature: Evaluator evaluator refs
       | key                            | value |
       | some-email-targeted-flag       | hi    |
       | some-other-email-targeted-flag | yes   |
+
+  @evaluator-refs @evaluator-refs-whitespace
+  Scenario Outline: Evaluator $ref resolves regardless of whitespace around the colon
+    Given an evaluator
+    And a String-flag with key "<key>" and a fallback value "fallback"
+    And a context containing a key "email", with type "String" and with value "<email>"
+    When the flag was evaluated with details
+    Then the resolved details value should be "<value>"
+    And the reason should be "TARGETING_MATCH"
+    Examples:
+      | key                                    | email                 | value |
+      | ref-whitespace-compact-flag            | ballmer@macrosoft.com | hi    |
+      | ref-whitespace-space-after-colon-flag  | ballmer@macrosoft.com | hi    |
+      | ref-whitespace-space-around-colon-flag | ballmer@macrosoft.com | hi    |
+      | ref-whitespace-compact-flag            | user@example.com      | bye   |
+      | ref-whitespace-space-after-colon-flag  | user@example.com      | bye   |
+      | ref-whitespace-space-around-colon-flag | user@example.com      | bye   |
+
+  @evaluator-refs @non-existent-evaluator-ref
+  Scenario: Ref to nonexistent evaluator yields parse error
+    Given an evaluator
+    And a String-flag with key "ref-to-nonexistent-evaluator-flag" and a fallback value "fallback"
+    When the flag was evaluated with details
+    Then the resolved details value should be "fallback"
+    And the error-code should be "PARSE_ERROR"
diff --git a/flags/evaluator-refs.json b/flags/evaluator-refs.json
index faad954..b2ca516 100644
--- a/flags/evaluator-refs.json
+++ b/flags/evaluator-refs.json
@@ -35,6 +35,78 @@
           "no"
         ]
       }
+    },
+    "ref-whitespace-compact-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hi": "hi",
+        "bye": "bye",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref":"is_ballmer"
+          },
+          "hi",
+          "bye"
+        ]
+      }
+    },
+    "ref-whitespace-space-after-colon-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hi": "hi",
+        "bye": "bye",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref": "is_ballmer"
+          },
+          "hi",
+          "bye"
+        ]
+      }
+    },
+    "ref-whitespace-space-around-colon-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hi": "hi",
+        "bye": "bye",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref" : "is_ballmer"
+          },
+          "hi",
+          "bye"
+        ]
+      }
+    },
+    "ref-to-nonexistent-evaluator-flag": {
+      "state": "ENABLED",
+      "variants": {
+        "hit": "hit",
+        "miss": "miss",
+        "fallback": "fallback"
+      },
+      "defaultVariant": "fallback",
+      "targeting": {
+        "if": [
+          {
+            "$ref": "nonexistent_evaluator"
+          },
+          "hit",
+          "miss"
+        ]
+      }
     }
   },
   "$evaluators": {
diff --git a/gherkin/targeting.feature b/gherkin/targeting.feature
index 71fb8b0..8a193b9 100644
--- a/gherkin/targeting.feature
+++ b/gherkin/targeting.feature
@@ -20,6 +20,29 @@ Feature: Targeting rules
       | some-email-targeted-flag       | hi    |
       | some-other-email-targeted-flag | yes   |
 
+  @evaluator-refs @evaluator-refs-whitespace
+  Scenario Outline: Evaluator $ref resolves regardless of whitespace around the colon
+    Given a String-flag with key "<key>" and a default value "fallback"
+    And a context containing a key "email", with type "String" and with value "<email>"
+    When the flag was evaluated with details
+    Then the resolved details value should be "<value>"
+    And the reason should be "TARGETING_MATCH"
+    Examples:
+      | key                                    | email                 | value |
+      | ref-whitespace-compact-flag            | ballmer@macrosoft.com | hi    |
+      | ref-whitespace-space-after-colon-flag  | ballmer@macrosoft.com | hi    |
+      | ref-whitespace-space-around-colon-flag | ballmer@macrosoft.com | hi    |
+      | ref-whitespace-compact-flag            | user@example.com      | bye   |
+      | ref-whitespace-space-after-colon-flag  | user@example.com      | bye   |
+      | ref-whitespace-space-around-colon-flag | user@example.com      | bye   |
+
+  @evaluator-refs @non-existent-evaluator-ref
+  Scenario: Ref to nonexistent evaluator yields parse error
+    Given a String-flag with key "ref-to-nonexistent-evaluator-flag" and a default value "fallback"
+    When the flag was evaluated with details
+    Then the resolved details value should be "fallback"
+    And the error-code should be "PARSE_ERROR"
+
   # custom operators
   # @fractional-v1: legacy float-based bucketing (abs(hash) / i32::MAX * 100)
   # @fractional-v2: high-precision integer bucketing ((hash * totalWeight) >> 32)