diff --git a/include/verilated.h b/include/verilated.h
index 81c174774..f64de2226 100644
--- a/include/verilated.h
+++ b/include/verilated.h
@@ -248,7 +248,7 @@ protected:
 public:
     /// Returns the VerilatedContext this model is instantiated under
     /// Used to get to e.g. simulation time via contextp()->time()
-    VerilatedContext* contextp() const { return &m_context; }
+    VerilatedContext* contextp() const VL_MT_SAFE { return &m_context; }
     /// Returns the hierarchical name of this module instance.
     virtual const char* hierName() const = 0;
     /// Returns the name of this model (the name of the generated model class).
@@ -718,7 +718,7 @@ public:
         lastContextp(contextp);
     }
     /// Return the VerilatedContext for the current thread
-    static VerilatedContext* threadContextp() {
+    static VerilatedContext* threadContextp() VL_MT_SAFE {
         if (VL_UNLIKELY(!t_s.t_contextp)) t_s.t_contextp = lastContextp();
         return t_s.t_contextp;
     }
diff --git a/include/verilated_imp.h b/include/verilated_imp.h
index 5684da3c5..e70fffd3b 100644
--- a/include/verilated_imp.h
+++ b/include/verilated_imp.h
@@ -441,7 +441,7 @@ protected:
     friend class Verilated;
 
     // MEMBERS
-    static VerilatedImpData& s() {  // Singleton
+    static VerilatedImpData& s() VL_MT_SAFE {  // Singleton
         static VerilatedImpData s_s;
         return s_s;
     }
diff --git a/include/verilated_vcd_c.h b/include/verilated_vcd_c.h
index 64469d430..94361115b 100644
--- a/include/verilated_vcd_c.h
+++ b/include/verilated_vcd_c.h
@@ -123,7 +123,7 @@ public:
 
     // ACCESSORS
     // Set size in bytes after which new file should be created.
-    void rolloverSize(uint64_t size) { m_rolloverSize = size; }
+    void rolloverSize(uint64_t size) VL_MT_SAFE { m_rolloverSize = size; }
 
     // METHODS - All must be thread safe
     // Open the file; call isOpen() to see if errors
diff --git a/include/verilated_vpi.cpp b/include/verilated_vpi.cpp
index 2fb4ecdba..f8640c64d 100644
--- a/include/verilated_vpi.cpp
+++ b/include/verilated_vpi.cpp
@@ -67,7 +67,7 @@ class VerilatedVpio VL_NOT_FINAL {
     // CONSTANTS
     // Magic value stored in front of object to detect double free etc
     // Must be odd, as aligned pointer can never be odd
-    static constexpr uint32_t activeMagic() { return 0xfeed100f; }
+    static constexpr uint32_t activeMagic() VL_PURE { return 0xfeed100f; }
 
     // MEM MANGLEMENT
     // Internal note: Globals may multi-construct, see verilated.cpp top.