diff --git a/Framework/Geometry/CMakeLists.txt b/Framework/Geometry/CMakeLists.txt
index bb96c2ea6bf5cf6e228b23fb7471c73c1b282923..f827de1f4cfcf4f8ef0ee5d4f986cea0eeff96b2 100644
--- a/Framework/Geometry/CMakeLists.txt
+++ b/Framework/Geometry/CMakeLists.txt
@@ -44,8 +44,14 @@ target_link_libraries (
 
 target_include_directories (
   CORSIKAgeometry
+  SYSTEM
   PUBLIC    ${EIGEN3_INCLUDE_DIR}
   INTERFACE ${EIGEN3_INCLUDE_DIR}
+  )
+
+target_include_directories (
+  CORSIKAgeometry
+  INTERFACE
   $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/include>
   $<INSTALL_INTERFACE:include/include>
   )
diff --git a/Processes/Pythia/CMakeLists.txt b/Processes/Pythia/CMakeLists.txt
index 3af574c892dd423cdef3b7f018265c9f6f3912af..b23c6d005f272854ac976104de24262996e98f47 100644
--- a/Processes/Pythia/CMakeLists.txt
+++ b/Processes/Pythia/CMakeLists.txt
@@ -27,7 +27,7 @@ set_target_properties (
   PROPERTIES
   VERSION ${PROJECT_VERSION}
   SOVERSION 1
-  PUBLIC_HEADER "${MODEL_HEADERS}"
+#  PUBLIC_HEADER "${MODEL_HEADERS}"
   )
 
 # target dependencies on other libraries (also the header onlys)
@@ -48,17 +48,12 @@ target_include_directories (
   $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/include>
   $<INSTALL_INTERFACE:include/include>
   )
-# do it again, since we want -isystem for pythia exteranls
-target_include_directories (
-  ProcessPythia
-  SYSTEM PUBLIC
-  ${PYTHIA8_INCLUDE_DIR}
-  )
 
 target_include_directories (
   ProcessPythia
-  PRIVATE
-  ${PYTHIA8_INCLUDE_DIR}
+  SYSTEM
+  PUBLIC ${PYTHIA8_INCLUDE_DIR}
+  INTERFACE ${PYTHIA8_INCLUDE_DIR}
   )
 
 install (
diff --git a/Processes/Sibyll/Decay.h b/Processes/Sibyll/Decay.h
index 76d61f7b5a44928a4a43d6d97aac7cfd231514eb..7e7a202e7c3172577c6a5662d09eb67bbb9433f2 100644
--- a/Processes/Sibyll/Decay.h
+++ b/Processes/Sibyll/Decay.h
@@ -15,6 +15,8 @@
 #include <corsika/particles/ParticleProperties.h>
 #include <corsika/process/DecayProcess.h>
 
+#include <vector>
+
 namespace corsika::process {
 
   namespace sibyll {