diff --git a/lib/bcc/ContextManager.cpp b/lib/bcc/ContextManager.cpp
index 16fbcf1..0fe9f78 100644
--- a/lib/bcc/ContextManager.cpp
+++ b/lib/bcc/ContextManager.cpp
@@ -168,7 +168,7 @@
 }
 
 
-bool ContextManager::isManagingContext(char *addr) {
+bool ContextManager::isManagingContext(char *addr) const {
   ssize_t slot = getSlotIndexFromAddress(addr);
 
   if (slot < 0) {
diff --git a/lib/bcc/ContextManager.h b/lib/bcc/ContextManager.h
index 0060012..4267a9e 100644
--- a/lib/bcc/ContextManager.h
+++ b/lib/bcc/ContextManager.h
@@ -45,7 +45,7 @@
 
   private:
     // Mutex lock for context slot occupation table
-    llvm::sys::Mutex mContextSlotOccupiedLock;
+    mutable llvm::sys::Mutex mContextSlotOccupiedLock;
 
     // Context slot occupation table
     bool mContextSlotOccupied[ContextSlotCount];
@@ -61,7 +61,7 @@
     char *allocateContext(char *addr, int imageFd, off_t imageOffset);
     void deallocateContext(char *addr);
 
-    bool isManagingContext(char *addr);
+    bool isManagingContext(char *addr) const;
 
   private:
     static ssize_t getSlotIndexFromAddress(char *addr);