diff --git a/CHANGELOG.md b/CHANGELOG.md
index ae68fdbfdc..70ffca7d3b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@
 ### Fixes
 
 - Fixed duplicate SentryMauiEventProcessors ([#3905](https://github.com/getsentry/sentry-dotnet/pull/3905))
+- Fixed invalid string.Format index in Debug logs for the DiagnosticSource integration ([#3923](https://github.com/getsentry/sentry-dotnet/pull/3923))
 
 ### Dependencies
 
diff --git a/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFCommandDiagnosticSourceHelper.cs b/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFCommandDiagnosticSourceHelper.cs
index baccd1366d..930c4a0d4a 100644
--- a/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFCommandDiagnosticSourceHelper.cs
+++ b/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFCommandDiagnosticSourceHelper.cs
@@ -34,7 +34,7 @@ private static void SetCommandId(ISpan span, Guid? commandId)
                     span.Operation == Operation &&
                     TryGetCommandId(span) == commandId);
         }
-        Options.LogWarning("No correlation id found for {1}.", Operation);
+        Options.LogWarning("No correlation id found for {0}.", Operation);
         return null;
     }
 
@@ -49,6 +49,6 @@ protected override void SetSpanReference(ISpan span, object? diagnosticSourceVal
             }
             return;
         }
-        Options.LogWarning("No correlation id can be set for {1}.", Operation);
+        Options.LogWarning("No correlation id can be set for {0}.", Operation);
     }
 }
diff --git a/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFConnectionDiagnosticSourceHelper.cs b/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFConnectionDiagnosticSourceHelper.cs
index 6f27286505..ba16b04ce2 100644
--- a/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFConnectionDiagnosticSourceHelper.cs
+++ b/src/Sentry.DiagnosticSource/Internal/DiagnosticSource/EFConnectionDiagnosticSourceHelper.cs
@@ -22,7 +22,7 @@ internal EFConnectionDiagnosticSourceHelper(IHub hub, SentryOptions options) : b
                     span.Operation == Operation &&
                     TryGetConnectionId(span) == connectionId);
         }
-        Options.LogWarning("No correlation id found for {1}.", Operation);
+        Options.LogWarning("No correlation id found for {0}.", Operation);
         return null;
     }