diff --git a/10/Dockerfile b/10/Dockerfile
index c2a841772f..56f52bcf3b 100644
--- a/10/Dockerfile
+++ b/10/Dockerfile
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		amd64 | i386 | ppc64el) \
diff --git a/11/Dockerfile b/11/Dockerfile
index 792bc262ea..686777ae51 100644
--- a/11/Dockerfile
+++ b/11/Dockerfile
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		amd64 | i386 | ppc64el) \
diff --git a/12/Dockerfile b/12/Dockerfile
index e8d188449e..9ba8573188 100644
--- a/12/Dockerfile
+++ b/12/Dockerfile
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		amd64 | arm64 | i386 | ppc64el) \
diff --git a/13/Dockerfile b/13/Dockerfile
index 07c7252365..d01eb76d3a 100644
--- a/13/Dockerfile
+++ b/13/Dockerfile
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		amd64 | arm64 | i386 | ppc64el) \
diff --git a/9.5/Dockerfile b/9.5/Dockerfile
index 092a6b623e..383e9af61b 100644
--- a/9.5/Dockerfile
+++ b/9.5/Dockerfile
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		amd64 | i386 | ppc64el) \
diff --git a/9.6/Dockerfile b/9.6/Dockerfile
index 3a3d9bcd00..1719cdd9ee 100644
--- a/9.6/Dockerfile
+++ b/9.6/Dockerfile
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		amd64 | i386 | ppc64el) \
diff --git a/Dockerfile-debian.template b/Dockerfile-debian.template
index 876229be59..ba6b9509ed 100644
--- a/Dockerfile-debian.template
+++ b/Dockerfile-debian.template
@@ -90,6 +90,18 @@ RUN set -ex; \
 # see note below about "*.pyc" files
 	export PYTHONDONTWRITEBYTECODE=1; \
 	\
+	{ \
+		echo 'Explanation: block installation of the "postgresql" metapackage, since it will almost always pull in something different than we expect'; \
+		echo 'Package: postgresql'; \
+		echo 'Pin: version *'; \
+		echo 'Pin-Priority: -10'; \
+		echo; \
+		echo 'Explanation: block installation of Debian postgresql packages, since we only want upstream'; \
+		echo 'Package: postgresql* libpq*'; \
+		echo 'Pin: release o=Debian'; \
+		echo 'Pin-Priority: -10'; \
+	} > /etc/apt/preferences.d/postgres.pref; \
+	\
 	dpkgArch="$(dpkg --print-architecture)"; \
 	case "$dpkgArch" in \
 		%%ARCH_LIST%%) \