diff --git a/crashlytics/src/appleMain/kotlin/co/touchlab/crashkios/crashlytics/CrashlyticsCallsActual.kt b/crashlytics/src/appleMain/kotlin/co/touchlab/crashkios/crashlytics/CrashlyticsCallsActual.kt
index 9723aa2..6e289ef 100644
--- a/crashlytics/src/appleMain/kotlin/co/touchlab/crashkios/crashlytics/CrashlyticsCallsActual.kt
+++ b/crashlytics/src/appleMain/kotlin/co/touchlab/crashkios/crashlytics/CrashlyticsCallsActual.kt
@@ -8,6 +8,9 @@ import kotlinx.cinterop.convert
 @OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
 actual class CrashlyticsCallsActual : CrashlyticsCalls {
 
+    init {
+        FIRCheckLinkDependencies()
+    }
 
     override fun logMessage(message: String) {
         FIRCrashlyticsLog(message)
diff --git a/crashlytics/src/nativeInterop/cinterop/crashlytics.def b/crashlytics/src/nativeInterop/cinterop/crashlytics.def
index 5391ae4..9cb9892 100644
--- a/crashlytics/src/nativeInterop/cinterop/crashlytics.def
+++ b/crashlytics/src/nativeInterop/cinterop/crashlytics.def
@@ -7,10 +7,8 @@ language = Objective-C
 
 extern void FIRCLSExceptionRecordNSException(NSException *exception) __attribute__((weak));
 
-void tryFIRCLSExceptionRecordNSException(NSException *exception) {
-    if (FIRCLSExceptionRecordNSException) {
-        FIRCLSExceptionRecordNSException(exception);
-    } else {
+void __verifyFIRCLSExceptionRecordNSExceptionExists(void) {
+    if (!FIRCLSExceptionRecordNSException) {
         @throw [NSException
             exceptionWithName:@"FIRFunctionNotFound"
             reason:@"Function 'FIRCLSExceptionRecordNSException' not available, make sure you're adding the Firebase Crashlytics dependency."
@@ -19,6 +17,11 @@ void tryFIRCLSExceptionRecordNSException(NSException *exception) {
     }
 }
 
+void tryFIRCLSExceptionRecordNSException(NSException *exception) {
+    __verifyFIRCLSExceptionRecordNSExceptionExists();
+    FIRCLSExceptionRecordNSException(exception);
+}
+
 #define LoadClass(name)\
     static Class objClass;\
     if (!objClass) {\
@@ -52,8 +55,23 @@ void* FIRMethodForSelector(id _Nonnull target, SEL _Nonnull selector) {
     }
 }
 
-id FIRExceptionModelWithNameAndReason(NSString* _Nonnull name, NSString* _Nonnull reason) {
+Class FIRExceptionModelClass(void) {
     LoadClass(FIRExceptionModel);
+    return objClass;
+}
+
+Class FIRStackFrameClass(void) {
+    LoadClass(FIRStackFrame);
+    return objClass;
+}
+
+Class FIRCrashlyticsClass(void) {
+    LoadClass(FIRCrashlytics);
+    return objClass;
+}
+
+id FIRExceptionModelWithNameAndReason(NSString* _Nonnull name, NSString* _Nonnull reason) {
+    Class objClass = FIRExceptionModelClass();
     SEL selector = NSSelectorFromString(@"exceptionModelWithName:reason:");
     id (*exceptionModelWithNameAndReason)(id, SEL, NSString*, NSString*) = FIRMethodForSelector(objClass, selector);
     return exceptionModelWithNameAndReason(objClass, selector, name, reason);
@@ -66,17 +84,21 @@ void FIRExceptionModelSetStackTrace(id exceptionModel, NSArray<id>* _Nonnull sta
 }
 
 id FIRStackFrameWithAddress(NSUInteger address) {
-    LoadClass(FIRStackFrame);
+    Class objClass = FIRStackFrameClass();
     SEL selector = NSSelectorFromString(@"stackFrameWithAddress:");
     id (*stackFrameWithAddress)(id, SEL, NSUInteger) = FIRMethodForSelector(objClass, selector);
     return stackFrameWithAddress(objClass, selector, address);
 }
 
-id FIRCrashlyticsInstance(void) {
-    LoadClass(FIRCrashlytics);
+id _Nullable FIRCrashlyticsInstanceOrNull(void) {
+    Class objClass = FIRCrashlyticsClass();
     SEL selector = NSSelectorFromString(@"crashlytics");
     id (*crashlytics)(id, SEL) = FIRMethodForSelector(objClass, selector);
-    id instance = crashlytics(objClass, selector);
+    return crashlytics(objClass, selector);
+}
+
+id _Nonnull FIRCrashlyticsInstance(void) {
+    id instance = FIRCrashlyticsInstanceOrNull();
     if (instance) {
         return instance;
     } else {
@@ -120,3 +142,12 @@ void FIRCrashlyticsSetCustomValue(NSString* _Nonnull key, id __nullable value) {
     void (*setCustomValueForKey)(id, SEL, id __nullable, NSString* _Nonnull) = FIRMethodForSelector(crashlytics, selector);
     setCustomValueForKey(crashlytics, selector, value, key);
 }
+
+void FIRCheckLinkDependencies(void) {
+    __verifyFIRCLSExceptionRecordNSExceptionExists();
+
+    // Load classes to verify we have them all
+    FIRExceptionModelClass();
+    FIRStackFrameClass();
+    FIRCrashlyticsClass();
+}