diff --git a/features/fixtures/docker-compose.yml b/features/fixtures/docker-compose.yml
index c2232de..6bc2f8d 100644
--- a/features/fixtures/docker-compose.yml
+++ b/features/fixtures/docker-compose.yml
@@ -19,6 +19,8 @@ services:
       - PARAMS_FILTERS
       - SYNCHRONOUS
       - SERVER_PORT
+      - BUGSNAG_SOURCE_ROOT
+      - BUGSNAG_PROJECT_PACKAGES
     restart: "no"
 
   autoconfigure:
@@ -72,6 +74,8 @@ services:
       - AUTO_CAPTURE_SESSIONS
       - SYNCHRONOUS
       - SERVER_PORT
+      - BUGSNAG_SOURCE_ROOT
+      - BUGSNAG_PROJECT_PACKAGES
     restart: "no"
     command: go run main.go
 
@@ -97,6 +101,8 @@ services:
       - AUTO_CAPTURE_SESSIONS
       - SYNCHRONOUS
       - SERVER_PORT
+      - BUGSNAG_SOURCE_ROOT
+      - BUGSNAG_PROJECT_PACKAGES
     restart: "no"
     command: go run main.go
 
@@ -121,6 +127,8 @@ services:
       - AUTO_CAPTURE_SESSIONS
       - SYNCHRONOUS
       - SERVER_PORT
+      - BUGSNAG_SOURCE_ROOT
+      - BUGSNAG_PROJECT_PACKAGES
     restart: "no"
     command: go run main.go
 
@@ -146,6 +154,8 @@ services:
       - AUTO_CAPTURE_SESSIONS
       - SYNCHRONOUS
       - SERVER_PORT
+      - BUGSNAG_SOURCE_ROOT
+      - BUGSNAG_PROJECT_PACKAGES
     restart: "no"
     command: go run main.go
 
@@ -173,5 +183,7 @@ services:
       - SYNCHRONOUS
       - SERVER_PORT
       - USE_PROPERTIES_FILE_CONFIG
+      - BUGSNAG_SOURCE_ROOT
+      - BUGSNAG_PROJECT_PACKAGES
     restart: "no"
     command: ./test/run.sh
diff --git a/features/handled.feature b/features/handled.feature
index 0cb7bf7..2555e34 100644
--- a/features/handled.feature
+++ b/features/handled.feature
@@ -2,6 +2,7 @@ Feature: Plain handled errors
 
 Background:
   Given I set environment variable "API_KEY" to "a35a2a72bd230ac0aa0f52715bbdc6aa"
+  Given I set environment variable "BUGSNAG_SOURCE_ROOT" to the app directory
   And I configure the bugsnag endpoint
   And I have built the service "app"
   And I set environment variable "AUTO_CAPTURE_SESSIONS" to "false"
@@ -14,7 +15,7 @@ Scenario: A handled error sends a report
   And the event "severity" equals "warning"
   And the event "severityReason.type" equals "handledError"
   And the exception is a PathError for request 0
-  And the "file" of stack frame 0 ends with "main.go"
+  And the "file" of stack frame 0 equals "main.go"
 
 Scenario: A handled error sends a report with a custom name
   Given I set environment variable "ERROR_CLASS" to "MyCustomErrorClass"
@@ -25,7 +26,7 @@ Scenario: A handled error sends a report with a custom name
   And the event "severity" equals "warning"
   And the event "severityReason.type" equals "handledError"
   And the exception "errorClass" equals "MyCustomErrorClass"
-  And the "file" of stack frame 0 ends with "main.go"
+  And the "file" of stack frame 0 equals "main.go"
 
 Scenario: Sending an event using a callback to modify report contents
   When I run the go service "app" with the test case "handled-with-callback"
@@ -35,7 +36,7 @@ Scenario: Sending an event using a callback to modify report contents
   And the event "severity" equals "info"
   And the event "severityReason.type" equals "userCallbackSetSeverity"
   And the event "context" equals "nonfatal.go:14"
-  And the "file" of stack frame 0 ends with "main.go"
+  And the "file" of stack frame 0 equals "main.go"
   And stack frame 0 contains a local function spanning 242 to 248
   And the "file" of stack frame 1 equals ">insertion<"
   And the "lineNumber" of stack frame 1 equals 0
@@ -48,7 +49,7 @@ Scenario: Marking an error as unhandled in a callback
   And the event "severity" equals "error"
   And the event "severityReason.type" equals "userCallbackSetSeverity"
   And the event "severityReason.unhandledOverridden" is true
-  And the "file" of stack frame 0 ends with "main.go"
+  And the "file" of stack frame 0 equals "main.go"
   And stack frame 0 contains a local function spanning 254 to 257
 
 Scenario: Unwrapping the causes of a handled error
@@ -59,11 +60,11 @@ Scenario: Unwrapping the causes of a handled error
   And the event "severity" equals "warning"
   And the event "exceptions.0.message" equals "terminate process"
   And the "lineNumber" of stack frame 0 equals 292
-  And the "file" of stack frame 0 ends with "main.go"
+  And the "file" of stack frame 0 equals "main.go"
   And the "method" of stack frame 0 equals "nestedHandledError"
   And the event "exceptions.1.message" equals "login failed"
-  And the event "exceptions.1.stacktrace.0.file" ends with "main.go"
+  And the event "exceptions.1.stacktrace.0.file" equals "main.go"
   And the event "exceptions.1.stacktrace.0.lineNumber" equals 312
   And the event "exceptions.2.message" equals "invalid token"
-  And the event "exceptions.2.stacktrace.0.file" ends with "main.go"
+  And the event "exceptions.2.stacktrace.0.file" equals "main.go"
   And the event "exceptions.2.stacktrace.0.lineNumber" equals 320
diff --git a/features/net-http/handled.feature b/features/net-http/handled.feature
index 87dbc37..4c9eb4c 100644
--- a/features/net-http/handled.feature
+++ b/features/net-http/handled.feature
@@ -2,6 +2,7 @@ Feature: Handled errors
 
 Background:
   Given I set environment variable "API_KEY" to "a35a2a72bd230ac0aa0f52715bbdc6aa"
+  Given I set environment variable "BUGSNAG_SOURCE_ROOT" to the app directory
   And I configure the bugsnag endpoint
   And I set environment variable "SERVER_PORT" to "4512"
   And I set environment variable "AUTO_CAPTURE_SESSIONS" to "false"
@@ -17,7 +18,7 @@ Scenario: A handled error sends a report
   And the event "severity" equals "warning" for request 0
   And the event "severityReason.type" equals "handledError" for request 0
   And the exception is a PathError for request 0
-  And the "file" of stack frame 0 ends with "main.go" for request 0
+  And the "file" of stack frame 0 equals "main.go" for request 0
 
 Scenario: A handled error sends a report with a custom name
   Given I set environment variable "ERROR_CLASS" to "MyCustomErrorClass"
@@ -31,4 +32,4 @@ Scenario: A handled error sends a report with a custom name
   And the event "severity" equals "warning" for request 0
   And the event "severityReason.type" equals "handledError" for request 0
   And the exception "errorClass" equals "MyCustomErrorClass" for request 0
-  And the "file" of stack frame 0 ends with "main.go" for request 0
+  And the "file" of stack frame 0 equals "main.go" for request 0
diff --git a/features/plain_features/panics.feature b/features/plain_features/panics.feature
index 7debc23..2f239a3 100644
--- a/features/plain_features/panics.feature
+++ b/features/plain_features/panics.feature
@@ -2,6 +2,7 @@ Feature: Panic handling
 
     Background:
       Given I set environment variable "API_KEY" to "a35a2a72bd230ac0aa0f52715bbdc6aa"
+      Given I set environment variable "BUGSNAG_SOURCE_ROOT" to the app directory
       And I configure the bugsnag endpoint
       And I have built the service "app"
       And I set environment variable "AUTO_CAPTURE_SESSIONS" to "false"
@@ -17,7 +18,7 @@ Feature: Panic handling
       And the exception "message" is one of:
         | interface conversion: interface is struct {}, not string      |
         | interface conversion: interface {} is struct {}, not string   |
-      And the "method" of stack frame 0 equals "unhandledCrash.func1"
-      And the "file" of stack frame 0 ends with "main.go"
-      And the "method" of stack frame 1 equals "unhandledCrash"
-      And the "file" of stack frame 1 ends with "main.go"
+      And the in-project frames of the stacktrace are:
+        | file    | method               |
+        | main.go | unhandledCrash.func1 |
+        | main.go | unhandledCrash       |