diff --git a/lang/cpp/src/defaultassuantransaction.cpp b/lang/cpp/src/defaultassuantransaction.cpp
index 2184f043..7a52c153 100644
--- a/lang/cpp/src/defaultassuantransaction.cpp
+++ b/lang/cpp/src/defaultassuantransaction.cpp
@@ -30,8 +30,6 @@
 #include "error.h"
 #include "data.h"
 
-#include <sstream>
-
 using namespace GpgME;
 
 DefaultAssuanTransaction::DefaultAssuanTransaction()
diff --git a/lang/cpp/src/gpgagentgetinfoassuantransaction.cpp b/lang/cpp/src/gpgagentgetinfoassuantransaction.cpp
index a05ff96f..e8524054 100644
--- a/lang/cpp/src/gpgagentgetinfoassuantransaction.cpp
+++ b/lang/cpp/src/gpgagentgetinfoassuantransaction.cpp
@@ -33,8 +33,6 @@
 
 #include <assert.h>
 
-#include <sstream>
-
 using namespace GpgME;
 
 GpgAgentGetInfoAssuanTransaction::GpgAgentGetInfoAssuanTransaction(InfoItem item)
diff --git a/lang/cpp/src/gpgrevokekeyeditinteractor.cpp b/lang/cpp/src/gpgrevokekeyeditinteractor.cpp
index f918bdb6..dfa3be16 100644
--- a/lang/cpp/src/gpgrevokekeyeditinteractor.cpp
+++ b/lang/cpp/src/gpgrevokekeyeditinteractor.cpp
@@ -31,7 +31,6 @@
 
 #include <gpgme.h>
 
-#include <sstream>
 #include <vector>
 
 // avoid conflict (msvc)
diff --git a/lang/cpp/src/scdgetinfoassuantransaction.cpp b/lang/cpp/src/scdgetinfoassuantransaction.cpp
index c2fbeed0..4a024905 100644
--- a/lang/cpp/src/scdgetinfoassuantransaction.cpp
+++ b/lang/cpp/src/scdgetinfoassuantransaction.cpp
@@ -31,7 +31,6 @@
 #include "data.h"
 #include "util.h"
 
-#include <sstream>
 #include <assert.h>
 
 using namespace GpgME;
diff --git a/lang/cpp/tests/run-verify.cpp b/lang/cpp/tests/run-verify.cpp
index ec431e5b..50131fb8 100644
--- a/lang/cpp/tests/run-verify.cpp
+++ b/lang/cpp/tests/run-verify.cpp
@@ -38,7 +38,6 @@
 #include "verificationresult.h"
 
 #include <memory>
-#include <sstream>
 #include <iostream>
 
 using namespace GpgME;
diff --git a/lang/cpp/tests/run-wkdlookup.cpp b/lang/cpp/tests/run-wkdlookup.cpp
index 71c4e704..fdd262d8 100644
--- a/lang/cpp/tests/run-wkdlookup.cpp
+++ b/lang/cpp/tests/run-wkdlookup.cpp
@@ -31,7 +31,6 @@
 #include "key.h"
 
 #include <memory>
-#include <sstream>
 #include <iostream>
 #include <thread>