diff --git a/app/demo-stm32h7-nucleo/app-h743.toml b/app/demo-stm32h7-nucleo/app-h743.toml
index a027771c3..ac5b9e9e5 100644
--- a/app/demo-stm32h7-nucleo/app-h743.toml
+++ b/app/demo-stm32h7-nucleo/app-h743.toml
@@ -138,7 +138,7 @@ start = true
 features = ["h743"]
 priority = 3
 name = "drv-stm32h7-rng"
-stacksize = 256
+stacksize = 512
 start = true
 task-slots = ["sys", "user_leds"]
 uses = ["rng"]
diff --git a/app/demo-stm32h7-nucleo/app-h753.toml b/app/demo-stm32h7-nucleo/app-h753.toml
index a7d0129c1..ebf12447d 100644
--- a/app/demo-stm32h7-nucleo/app-h753.toml
+++ b/app/demo-stm32h7-nucleo/app-h753.toml
@@ -189,7 +189,7 @@ start = true
 features = ["h753"]
 priority = 3
 name = "drv-stm32h7-rng"
-stacksize = 256
+stacksize = 512
 start = true
 task-slots = ["sys", "user_leds"]
 uses = ["rng"]
diff --git a/app/gemini-bu/app.toml b/app/gemini-bu/app.toml
index c223105eb..e0cd5e24b 100644
--- a/app/gemini-bu/app.toml
+++ b/app/gemini-bu/app.toml
@@ -158,7 +158,7 @@ name = "drv-stm32h7-rng"
 priority = 6
 uses = ["rng"]
 start = true
-stacksize = 256
+stacksize = 512
 task-slots = ["sys", "user_leds"]
 
 [tasks.update_server]
diff --git a/app/gimletlet/base-gimletlet2.toml b/app/gimletlet/base-gimletlet2.toml
index 98ae9139e..83f668d6c 100644
--- a/app/gimletlet/base-gimletlet2.toml
+++ b/app/gimletlet/base-gimletlet2.toml
@@ -107,7 +107,7 @@ name = "drv-stm32h7-rng"
 priority = 6
 uses = ["rng"]
 start = true
-stacksize = 256
+stacksize = 512
 task-slots = ["sys", "user_leds"]
 
 [tasks.update_server]
diff --git a/app/sidecar/base.toml b/app/sidecar/base.toml
index d4eb1ff91..eb3861346 100644
--- a/app/sidecar/base.toml
+++ b/app/sidecar/base.toml
@@ -59,7 +59,7 @@ name = "drv-stm32h7-rng"
 priority = 6
 uses = ["rng"]
 start = true
-stacksize = 256
+stacksize = 512
 task-slots = ["sys"]
 
 [tasks.update_server]
diff --git a/build/xtask/src/dist.rs b/build/xtask/src/dist.rs
index 8b0ef6ca4..1ecc6c9c5 100644
--- a/build/xtask/src/dist.rs
+++ b/build/xtask/src/dist.rs
@@ -1236,17 +1236,24 @@ pub fn get_max_stack(
         }
         chunks.extend(chunk); // don't forget the trailing chunk!
 
+        let frame_size = addr_to_frame_size.get(&base_addr).copied();
         let mut calls = BTreeSet::new();
         for (addr, chunk) in chunks {
             let instrs = cs
                 .disasm_all(&chunk, addr.into())
                 .map_err(|e| anyhow!("disassembly failed: {e:?}"))?;
-            for instr in instrs.iter() {
+            for (i, instr) in instrs.iter().enumerate() {
                 let detail = cs.insn_detail(instr).map_err(|e| {
                     anyhow!("could not get instruction details: {e}")
                 })?;
+
+                // Detect tail calls, which are jumps at the final instruction
+                // when the function itself has no stack frame.
+                let can_tail = frame_size == Some(0) && i == instrs.len() - 1;
                 if detail.groups().iter().any(|g| {
                     g == &InsnGroupId(InsnGroupType::CS_GRP_CALL as u8)
+                        || (g == &InsnGroupId(InsnGroupType::CS_GRP_JUMP as u8)
+                            && can_tail)
                 }) {
                     let arch = detail.arch_detail();
                     let ops = arch.operands();
@@ -1290,7 +1297,7 @@ pub fn get_max_stack(
             FunctionData {
                 name,
                 short_name,
-                frame_size: addr_to_frame_size.get(&base_addr).map(|i| *i),
+                frame_size,
                 calls,
             },
         );