diff --git a/src/conn.cpp b/src/conn.cpp
index a5479e3..1767b25 100644
--- a/src/conn.cpp
+++ b/src/conn.cpp
@@ -52,7 +52,7 @@ const char* ConnBase::peerLabel() const
 void ConnBase::connect(bufferevent* bev)
 {
     if(!bev)
-        throw std::bad_alloc();
+        throw BAD_ALLOC();
     assert(!this->bev && state==Holdoff);
 
     this->bev.reset(bev);
diff --git a/src/evhelper.cpp b/src/evhelper.cpp
index 103f0a0..e88d613 100644
--- a/src/evhelper.cpp
+++ b/src/evhelper.cpp
@@ -951,7 +951,7 @@ bool EvOutBuf::refill(size_t more)
     vec.iov_len  = base ? pos - base : 0u;
 
     if(base && evbuffer_commit_space(backing, &vec, 1))
-        throw std::bad_alloc(); // leak?
+        throw BAD_ALLOC(); // leak?
 
     limit = base = pos = nullptr;
 
@@ -975,7 +975,7 @@ bool EvInBuf::refill(size_t needed)
 
     // drain consumed
     if(base && evbuffer_drain(backing, pos-base))
-        throw std::bad_alloc();
+        throw BAD_ALLOC();
 
     limit = base = pos = nullptr;
 
@@ -1016,7 +1016,7 @@ void to_evbuf(evbuffer *buf, const Header& H, bool be)
     EvOutBuf M(be, buf, 8);
     to_wire(M, H);
     if(!M.good())
-        throw std::bad_alloc();
+        throw BAD_ALLOC();
 }
 
 } // namespace impl
diff --git a/src/evhelper.h b/src/evhelper.h
index 1ef7dc2..658a6f7 100644
--- a/src/evhelper.h
+++ b/src/evhelper.h
@@ -63,7 +63,7 @@ struct owned_ptr : public std::unique_ptr<T>
     constexpr owned_ptr() {}
     explicit owned_ptr(T* ptr) : std::unique_ptr<T>(ptr) {
         if(!*this)
-            throw std::bad_alloc();
+            throw BAD_ALLOC();
     }
 };
 
diff --git a/src/serverconn.cpp b/src/serverconn.cpp
index 8a1bf4d..fb981bb 100644
--- a/src/serverconn.cpp
+++ b/src/serverconn.cpp
@@ -101,7 +101,7 @@ ServerConn::ServerConn(ServIface* iface, evutil_socket_t sock, struct sockaddr *
         assert(M.good() && H.good());
 
         if(evbuffer_add(tx, buf.data(), M.save()-buf.data()))
-            throw std::bad_alloc();
+            throw BAD_ALLOC();
 
         statTx += M.save()-buf.data();
     }
diff --git a/src/unittest.cpp b/src/unittest.cpp
index 1be9da8..52a153d 100644
--- a/src/unittest.cpp
+++ b/src/unittest.cpp
@@ -1,4 +1,4 @@
-/**
+/**
  * Copyright - See the COPYRIGHT that is included with this distribution.
  * pvxs is distributed subject to a Software License Agreement found
  * in file LICENSE that is included with this distribution.
@@ -18,6 +18,10 @@
 #endif
 
 #include <epicsUnitTest.h>
+#include <epicsString.h>
+#define epicsStdioStdStreams
+#define epicsStdioStdPrintfEtc
+#include <epicsStdio.h>
 
 #include "pvxs/unittest.h"
 #include "utilpvt.h"
@@ -37,6 +41,29 @@ void testSetup()
 #endif
 }
 
+namespace impl {
+loc_bad_alloc::loc_bad_alloc(const char *file, int line)
+{
+    if(auto sep = strrchr(file, '/')) {
+        file = sep+1;
+    }
+#ifdef _WIN32
+    if(auto sep = strrchr(file, '\\')) {
+        file = sep+1;
+    }
+#endif
+    epicsSnprintf(msg, sizeof(msg)-1u, "bad_alloc %s:%d", file, line);
+}
+
+loc_bad_alloc::~loc_bad_alloc() {}
+
+const char* loc_bad_alloc::what() const noexcept
+{
+    return msg;
+}
+
+} // namespace impl
+
 void cleanup_for_valgrind()
 {
     for(auto& pair : instanceSnapshot()) {
diff --git a/src/util.cpp b/src/util.cpp
index 9c6ce84..ebb915f 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -236,7 +236,7 @@ struct SocketPair {
         auto err = evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, s);
 #endif
         if(err)
-            throw std::bad_alloc();
+            throw BAD_ALLOC();
     }
     ~SocketPair() {
         epicsSocketDestroy(s[0]);
diff --git a/src/utilpvt.h b/src/utilpvt.h
index 38c49f6..b17fd50 100644
--- a/src/utilpvt.h
+++ b/src/utilpvt.h
@@ -56,6 +56,21 @@ struct promote_print<int8_t> { static int op(const char& v) { return v; }};
 template<>
 struct promote_print<uint8_t> { static unsigned op(const char& v) { return v; }};
 
+/* specialization of bad_alloc which notes the location from which
+ * the exception originates.
+ */
+struct PVXS_API loc_bad_alloc final : public std::bad_alloc
+{
+    loc_bad_alloc(const char *file, int line);
+    virtual ~loc_bad_alloc();
+
+    virtual const char* what() const noexcept override final;
+
+private:
+    char msg[64];
+};
+#define BAD_ALLOC() ::pvxs::impl::loc_bad_alloc(__FILE__, __LINE__)
+
 //! in-line string builder (eg. for exception messages)
 //! eg. @code throw std::runtime_error(SB()<<"Some message"<<42); @endcode
 struct SB {