diff --git config/system-headers config/system-headers
index 432cba6..18a9627 100644
--- config/system-headers
+++ config/system-headers
@@ -1157,3 +1157,4 @@ unicode/uenum.h
 unicode/unum.h
 unicode/ustring.h
 #endif
+libutil.h
diff --git js/src/config/system-headers js/src/config/system-headers
index 432cba6..18a9627 100644
--- js/src/config/system-headers
+++ js/src/config/system-headers
@@ -1157,3 +1157,4 @@ unicode/uenum.h
 unicode/unum.h
 unicode/ustring.h
 #endif
+libutil.h
diff --git toolkit/library/Makefile.in toolkit/library/Makefile.in
index 9975621..b4b037d 100644
--- toolkit/library/Makefile.in
+++ toolkit/library/Makefile.in
@@ -289,6 +289,10 @@ OS_LIBS += $(call EXPAND_LIBNAME,kvm)
 EXTRA_DSO_LDOPTS += -Wl,--warn-unresolved-symbols
 endif
 
+ifeq ($(OS_ARCH),FreeBSD)
+OS_LIBS += $(call EXPAND_LIBNAME,util)
+endif
+
 ifeq ($(OS_ARCH),WINNT)
 OS_LIBS += $(call EXPAND_LIBNAME,shell32 ole32 version winspool comdlg32 imm32 msimg32 shlwapi psapi ws2_32 dbghelp rasapi32 rasdlg iphlpapi uxtheme setupapi secur32 sensorsapi portabledeviceguids windowscodecs wininet wbemuuid)
 ifdef ACCESSIBILITY
diff --git xpcom/base/nsMemoryReporterManager.cpp xpcom/base/nsMemoryReporterManager.cpp
index b8147c8..0ffb34e 100644
--- xpcom/base/nsMemoryReporterManager.cpp
+++ xpcom/base/nsMemoryReporterManager.cpp
@@ -153,6 +153,43 @@ static nsresult GetResidentFast(int64_t 
     return GetResident(n);
 }
 
+#ifdef __FreeBSD__
+#include <libutil.h>
+
+static nsresult
+GetKinfoVmentrySelf(int64_t* prss)
+{
+    int cnt;
+    struct kinfo_vmentry *vmmap, *kve;
+    if ((vmmap = kinfo_getvmmap(getpid(), &cnt)) == NULL)
+        return NS_ERROR_FAILURE;
+
+    if (prss)
+        *prss = 0;
+
+    for (int i = 0; i < cnt; i++) {
+        kve = &vmmap[i];
+        if (prss)
+            *prss += kve->kve_private_resident;
+    }
+
+    free(vmmap);
+    return NS_OK;
+}
+
+#define HAVE_PRIVATE_REPORTER
+static nsresult
+GetPrivate(int64_t* aN)
+{
+    int64_t priv;
+    nsresult rv = GetKinfoVmentrySelf(&priv);
+    if (NS_SUCCEEDED(rv))
+        *aN = priv * getpagesize();
+
+    return NS_OK;
+}
+#endif // FreeBSD
+
 #elif defined(SOLARIS)
 
 #include <procfs.h>
@@ -327,6 +364,24 @@ static nsresult GetResidentFast(int64_t 
 }
 
 #define HAVE_PRIVATE_REPORTER
+static nsresult
+GetPrivate(int64_t* aN)
+{
+    PROCESS_MEMORY_COUNTERS_EX pmcex;
+    pmcex.cb = sizeof(PROCESS_MEMORY_COUNTERS_EX);
+
+    if (!GetProcessMemoryInfo(
+            GetCurrentProcess(),
+            (PPROCESS_MEMORY_COUNTERS) &pmcex, sizeof(pmcex))) {
+        return NS_ERROR_FAILURE;
+    }
+
+    *aN = pmcex.PrivateUsage;
+    return NS_OK;
+}
+#endif  // XP_<PLATFORM>
+
+#ifdef HAVE_PRIVATE_REPORTER
 class PrivateReporter MOZ_FINAL : public MemoryReporterBase
 {
 public:
@@ -339,21 +394,10 @@ public:
 
     NS_IMETHOD GetAmount(int64_t *aAmount)
     {
-        PROCESS_MEMORY_COUNTERS_EX pmcex;
-        pmcex.cb = sizeof(PROCESS_MEMORY_COUNTERS_EX);
-
-        if (!GetProcessMemoryInfo(
-                GetCurrentProcess(),
-                (PPROCESS_MEMORY_COUNTERS) &pmcex, sizeof(pmcex))) {
-            return NS_ERROR_FAILURE;
-        }
-
-        *aAmount = pmcex.PrivateUsage;
-        return NS_OK;
+        return GetPrivate(aAmount);
     }
 };
-
-#endif  // XP_<PLATFORM>
+#endif
 
 #ifdef HAVE_VSIZE_AND_RESIDENT_REPORTERS
 class VsizeReporter MOZ_FINAL : public MemoryReporterBase