diff --git a/events/codepipeline_cloudwatch.go b/events/codepipeline_cloudwatch.go
index 41340c4e..24d4a342 100644
--- a/events/codepipeline_cloudwatch.go
+++ b/events/codepipeline_cloudwatch.go
@@ -1,6 +1,7 @@
 package events
 
 import (
+	"encoding/json"
 	"time"
 )
 
@@ -79,8 +80,9 @@ type CodePipelineEventBridgeEvent = CodePipelineCloudWatchEvent
 type CodePipelineEventDetail struct {
 	Pipeline string `json:"pipeline"`
 
-	// From live testing this is always int64 not string as documented
-	Version int64 `json:"version"`
+	// Version is the pipeline version number. AWS may send this as an integer (e.g. 1)
+	// or a float (e.g. 2.0). Use Version.Int64() or Version.Float64() to extract the value.
+	Version json.Number `json:"version"`
 
 	ExecutionID string `json:"execution-id"`
 
@@ -104,8 +106,8 @@ type CodePipelineEventDetailType struct {
 
 	Provider string `json:"provider"`
 
-	// From published EventBridge schema registry this is always int64 not string as documented
-	Version int64 `json:"version"`
+	// Version is a string per the AWS EventBridge schema registry and confirmed by the service team.
+	Version string `json:"version"`
 }
 
 type CodePipelineEventDetailExecutionResult struct {
diff --git a/events/codepipeline_cloudwatch_test.go b/events/codepipeline_cloudwatch_test.go
index 13321980..fbd7002c 100644
--- a/events/codepipeline_cloudwatch_test.go
+++ b/events/codepipeline_cloudwatch_test.go
@@ -29,7 +29,7 @@ func TestUnmarshalCodePipelineEvent(t *testing.T) {
 				},
 				Detail: CodePipelineEventDetail{
 					Pipeline:    "myPipeline",
-					Version:     1,
+					Version:     "1",
 					ExecutionID: "01234567-0123-0123-0123-012345678901",
 					Stage:       "Prod",
 					Action:      "myAction",
@@ -39,7 +39,7 @@ func TestUnmarshalCodePipelineEvent(t *testing.T) {
 						Owner:    "AWS",
 						Category: "Deploy",
 						Provider: "CodeDeploy",
-						Version:  1,
+						Version:  "1",
 					},
 				},
 			},
@@ -59,7 +59,7 @@ func TestUnmarshalCodePipelineEvent(t *testing.T) {
 				},
 				Detail: CodePipelineEventDetail{
 					Pipeline:    "myPipeline",
-					Version:     1,
+					Version:     "1",
 					ExecutionID: "01234567-0123-0123-0123-012345678901",
 					State:       "STARTED",
 				},
@@ -80,12 +80,44 @@ func TestUnmarshalCodePipelineEvent(t *testing.T) {
 				},
 				Detail: CodePipelineEventDetail{
 					Pipeline:    "myPipeline",
-					Version:     1,
+					Version:     "1",
 					ExecutionID: "01234567-0123-0123-0123-012345678901",
 					State:       "STARTED",
 				},
 			},
 		},
+		{
+			// AWS may send detail.version as a float (e.g. 2.0) rather than an integer.
+			// Regression test for https://github.com/aws/aws-lambda-go/issues/552
+			input: "testdata/codepipeline-action-execution-stage-change-event-float-version.json",
+			expect: CodePipelineCloudWatchEvent{
+				Version:    "0",
+				ID:         "CWE-event-id",
+				DetailType: "CodePipeline Action Execution State Change",
+				Source:     "aws.codepipeline",
+				AccountID:  "123456789012",
+				Time:       time.Date(2017, 04, 22, 3, 31, 47, 0, time.UTC),
+				Region:     "us-east-1",
+				Resources: []string{
+					"arn:aws:codepipeline:us-east-1:123456789012:pipeline:myPipeline",
+				},
+				Detail: CodePipelineEventDetail{
+					Pipeline:    "myPipeline",
+					Version:     "2.0",
+					ExecutionID: "01234567-0123-0123-0123-012345678901",
+					Stage:       "Prod",
+					Action:      "myAction",
+					State:       "STARTED",
+					Region:      "us-west-2",
+					Type: CodePipelineEventDetailType{
+						Owner:    "AWS",
+						Category: "Deploy",
+						Provider: "CodeDeploy",
+						Version:  "1",
+					},
+				},
+			},
+		},
 	}
 
 	for _, testcase := range tests {
diff --git a/events/testdata/codepipeline-action-execution-stage-change-event-float-version.json b/events/testdata/codepipeline-action-execution-stage-change-event-float-version.json
new file mode 100644
index 00000000..4a60fb65
--- /dev/null
+++ b/events/testdata/codepipeline-action-execution-stage-change-event-float-version.json
@@ -0,0 +1,27 @@
+{
+  "version": "0",
+  "id": "CWE-event-id",
+  "detail-type": "CodePipeline Action Execution State Change",
+  "source": "aws.codepipeline",
+  "account": "123456789012",
+  "time": "2017-04-22T03:31:47Z",
+  "region": "us-east-1",
+  "resources": [
+    "arn:aws:codepipeline:us-east-1:123456789012:pipeline:myPipeline"
+  ],
+  "detail": {
+    "pipeline": "myPipeline",
+    "version": 2.0,
+    "execution-id": "01234567-0123-0123-0123-012345678901",
+    "stage": "Prod",
+    "action": "myAction",
+    "state": "STARTED",
+    "region":"us-west-2",
+    "type": {
+      "owner": "AWS",
+      "category": "Deploy",
+      "provider": "CodeDeploy",
+      "version": "1"
+    }
+  }
+}
diff --git a/events/testdata/codepipeline-action-execution-stage-change-event.json b/events/testdata/codepipeline-action-execution-stage-change-event.json
index 826fa77a..9d41990f 100644
--- a/events/testdata/codepipeline-action-execution-stage-change-event.json
+++ b/events/testdata/codepipeline-action-execution-stage-change-event.json
@@ -21,7 +21,7 @@
       "owner": "AWS",
       "category": "Deploy",
       "provider": "CodeDeploy",
-      "version": 1
+      "version": "1"
     }
   }
 }
\ No newline at end of file