diff --git a/Source/BugsnagKeys.h b/Source/BugsnagKeys.h
index 5af422432..f63e23880 100644
--- a/Source/BugsnagKeys.h
+++ b/Source/BugsnagKeys.h
@@ -52,6 +52,16 @@ static NSString *const BSGKeyIsLR = @"isLR";
 static NSString *const BSGKeyMachoFile = @"machoFile";
 static NSString *const BSGKeyMachoUUID = @"machoUUID";
 static NSString *const BSGKeyMachoVMAddress = @"machoVMAddress";
+static NSString *const BSGKeyImageAddress = @"image_addr";
+static NSString *const BSGKeyImageVmAddress = @"image_vmaddr";
+static NSString *const BSGKeyInstructionAddress = @"instruction_addr";
+static NSString *const BSGKeySymbolAddress = @"symbol_addr";
+static NSString *const BSGKeyObjectAddress = @"object_addr";
+static NSString *const BSGKeyFrameAddress = @"frameAddress";
+static NSString *const BSGKeyObjectName = @"object_name";
+static NSString *const BSGKeyUuid = @"uuid";
+static NSString *const BSGKeyMethod = @"method";
+static NSString *const BSGKeySymbolName = @"symbol_name";
 static NSString *const BSGKeyCppException = @"cpp_exception";
 static NSString *const BSGKeyExceptionName = @"exception_name";
 static NSString *const BSGKeyMach = @"mach";
diff --git a/Source/BugsnagStackframe.m b/Source/BugsnagStackframe.m
index 123c7d643..31d612f44 100644
--- a/Source/BugsnagStackframe.m
+++ b/Source/BugsnagStackframe.m
@@ -14,7 +14,7 @@ @implementation BugsnagStackframe
 
 + (NSDictionary *_Nullable)findImageAddr:(unsigned long)addr inImages:(NSArray *)images {
     for (NSDictionary *image in images) {
-        if ([(NSNumber *)image[@"image_addr"] unsignedLongValue] == addr) {
+        if ([(NSNumber *)image[BSGKeyImageAddress] unsignedLongValue] == addr) {
             return image;
         }
     }
@@ -24,33 +24,33 @@ + (NSDictionary *_Nullable)findImageAddr:(unsigned long)addr inImages:(NSArray *
 + (BugsnagStackframe *)frameFromDict:(NSDictionary *)dict
                           withImages:(NSArray *)binaryImages {
     BugsnagStackframe *frame = [BugsnagStackframe new];
-    frame.frameAddress = [dict[@"instruction_addr"] unsignedLongValue];
-    frame.symbolAddress = [dict[@"symbol_addr"] unsignedLongValue];
-    frame.machoLoadAddress = [dict[@"object_addr"] unsignedLongValue];
-    frame.machoFile = dict[@"object_name"];
-    frame.method = dict[@"symbol_name"];
+    frame.frameAddress = [dict[BSGKeyInstructionAddress] unsignedLongValue];
+    frame.symbolAddress = [dict[BSGKeySymbolAddress] unsignedLongValue];
+    frame.machoLoadAddress = [dict[BSGKeyObjectAddress] unsignedLongValue];
+    frame.machoFile = dict[BSGKeyObjectName];
+    frame.method = dict[BSGKeySymbolName];
     frame.isPc = [dict[BSGKeyIsPC] boolValue];
     frame.isLr = [dict[BSGKeyIsLR] boolValue];
 
     NSDictionary *image = [self findImageAddr:frame.machoLoadAddress inImages:binaryImages];
 
     if (image != nil) {
-        frame.machoUuid = image[@"uuid"];
-        frame.machoVmAddress = [image[@"image_vmaddr"] unsignedLongValue];
+        frame.machoUuid = image[BSGKeyUuid];
+        frame.machoVmAddress = [image[BSGKeyImageVmAddress] unsignedLongValue];
         return frame;
     } else { // invalid frame, skip
         return nil;
     }
 }
 
-- (NSDictionary *)toDict {
+- (NSDictionary *)toDictionary {
     NSMutableDictionary *dict = [NSMutableDictionary new];
     BSGDictInsertIfNotNil(dict, self.machoFile, BSGKeyMachoFile);
-    BSGDictInsertIfNotNil(dict, self.method, @"method");
+    BSGDictInsertIfNotNil(dict, self.method, BSGKeyMethod);
     BSGDictInsertIfNotNil(dict, self.machoUuid, BSGKeyMachoUUID);
 
     NSString *frameAddr = [NSString stringWithFormat:BSGKeyFrameAddrFormat, self.frameAddress];
-    BSGDictSetSafeObject(dict, frameAddr, @"frameAddress");
+    BSGDictSetSafeObject(dict, frameAddr, BSGKeyFrameAddress);
 
     NSString *symbolAddr = [NSString stringWithFormat:BSGKeyFrameAddrFormat, self.symbolAddress];
     BSGDictSetSafeObject(dict, symbolAddr, BSGKeySymbolAddr);
diff --git a/Source/BugsnagStacktrace.h b/Source/BugsnagStacktrace.h
index e7446f49e..d789498a1 100644
--- a/Source/BugsnagStacktrace.h
+++ b/Source/BugsnagStacktrace.h
@@ -20,6 +20,4 @@
 
 - (NSArray *)toArray;
 
-@property NSMutableArray<BugsnagStackframe *> *trace;
-
 @end
diff --git a/Source/BugsnagStacktrace.m b/Source/BugsnagStacktrace.m
index 836b1c6fd..47167d6af 100644
--- a/Source/BugsnagStacktrace.m
+++ b/Source/BugsnagStacktrace.m
@@ -8,13 +8,15 @@
 
 #import "BugsnagStacktrace.h"
 #import "BugsnagStackframe.h"
-#import "BugsnagCollections.h"
-#import "BugsnagKeys.h"
 
 @interface BugsnagStackframe ()
 + (BugsnagStackframe *)frameFromDict:(NSDictionary *)dict
                           withImages:(NSArray *)binaryImages;
-- (NSDictionary *)toDict;
+- (NSDictionary *)toDictionary;
+@end
+
+@interface BugsnagStacktrace ()
+@property NSMutableArray<BugsnagStackframe *> *trace;
 @end
 
 @implementation BugsnagStacktrace
@@ -38,7 +40,7 @@ - (instancetype)initWithTrace:(NSArray<NSDictionary *> *)trace
 - (NSArray *)toArray {
     NSMutableArray *array = [NSMutableArray new];
     for (BugsnagStackframe *frame in self.trace) {
-        [array addObject:[frame toDict]];
+        [array addObject:[frame toDictionary]];
     }
     return array;
 }
diff --git a/Tests/BugsnagStackframeTest.m b/Tests/BugsnagStackframeTest.m
index 0cc22c1a8..0f0aa6d27 100644
--- a/Tests/BugsnagStackframeTest.m
+++ b/Tests/BugsnagStackframeTest.m
@@ -10,7 +10,7 @@
 #import "BugsnagStackframe.h"
 
 @interface BugsnagStackframe ()
-- (NSDictionary *)toDict;
+- (NSDictionary *)toDictionary;
 + (BugsnagStackframe *)frameFromDict:(NSDictionary *)dict withImages:(NSArray *)binaryImages;
 @end
 
@@ -52,7 +52,7 @@ - (void)testStackframeFromDict {
 
 - (void)testStackframeToDict {
     BugsnagStackframe *frame = [BugsnagStackframe frameFromDict:self.frameDict withImages:self.binaryImages];
-    NSDictionary *dict = [frame toDict];
+    NSDictionary *dict = [frame toDictionary];
     XCTAssertEqualObjects(@"-[BugsnagClient notify:handledState:block:]", dict[@"method"]);
     XCTAssertEqualObjects(@"/Users/foo/Bugsnag.h", dict[@"machoFile"]);
     XCTAssertEqualObjects(@"B6D80CB5-A772-3D2F-B5A1-A3A137B8B58F", dict[@"machoUUID"]);
diff --git a/Tests/BugsnagStacktraceTest.m b/Tests/BugsnagStacktraceTest.m
index 8a74a14c4..93e025428 100644
--- a/Tests/BugsnagStacktraceTest.m
+++ b/Tests/BugsnagStacktraceTest.m
@@ -15,6 +15,10 @@ @interface BugsnagStacktraceTest : XCTestCase
 @property NSArray *binaryImages;
 @end
 
+@interface BugsnagStacktrace ()
+@property NSMutableArray<BugsnagStackframe *> *trace;
+@end
+
 @implementation BugsnagStacktraceTest
 
 - (void)setUp {